C Programming Test

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C Programming Test

1 .

A preprocessor directive is a message from programmer to the preprocessor.

A.True B.False

Answer: Option A Explanation:

True, the programmer tells the compiler to include the preprocessor when compiling.

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2 .

What will be the output of the program?

#include<stdio.h> int main()

{

int i=2;

printf("%d, %d\n", ++i, ++i); return 0;

}

A.3, ₄ B.4, ₃ C.4, ₄

D.Output may vary from compiler to compiler

Answer: Option D Explanation:

The order of evaluation of arguments passed to a function call is unspecified.

Anyhow, we consider ++i, ++i are Right-to-Left associativity. The output of the program is 4, 3.

In TurboC, the output will be 4, 3. In GCC, the output will be 4, 4.

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3 .

Consider the following program and what will be content of t?

#include<stdio.h> int main() { FILE *fp; int t; fp = fopen("DUMMY.C", "w"); t = fileno(fp); printf("%d\n", t); return 0; }

A.size of "DUMMY.C" file

B.The handle associated with "DUMMY.C" file C.Garbage value

D.Error in _fileno()

Answer: Option B Explanation:

fp = fopen("DUMMY.C", "w"); A file DUMMY.C is opened in write mode and returns the file

pointer to fp

t = fileno(fp); returns the handle for the fp stream and it stored in the variable t printf("%d\n", t); It prints the handle number.

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4

. Point out the error in the following program.

#include<stdio.h> void display(int (*ff)()); int main() { int show(); int (*f)(); f = show; display(f); return 0; } void display(int (*ff)()) { (*ff)(); }

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int show() {

printf("IndiaBIX"); }

A.Error: invalid parameter in function

display()

B.Error: invalid function call _f=show; C.No error and prints "IndiaBIX" D.No error and prints nothing.

Answer: Option C

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5 .

What will be the output of the program (myprog.c) given below if it is executed from the command line?

cmd> myprog friday tuesday sunday

/* myprog.c */ #include<stdio.h>

int main(int argc, char *argv[]) { printf("%c", *++argv[1]); return 0; } A.r B.f C.m D.y Answer: Option A

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6 .

If the following program (myproc.c) is present in the directory "C:\TC" then what will be output of the program if run it from DOS shell?

/* myproc.c */ #include<stdio.h>

int main(int argc, char *argv[]) { printf("%s", argv[0]); return 0; } A.SAMPLE.C B.C:\TC\MYPROC.EXE C.C:\TC D.Error

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In order to execute it from DOS shell, we have to run the created EXE file by entering the exe file name as C:\TC>myproc <enter>.

7 .

Which of the following is correct about err used in the declaration given below?

typedef enum error { warning, test, exception } err;

A.It is a typedef for enum error. B.It is a variable of type enum error. C.The statement is erroneous. D.It is a structure.

A typedef gives a new name to an existing data type. So err is a new name for enum error.

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8 .

#include<stdio.h> int main() { int i=3; switch(i) { case 1: printf("Hello\n"); case 2: printf("Hi\n"); case 3: continue; default: printf("Bye\n"); } return 0; }

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C.No output D.Hello Hi

The keyword continue cannot be used in switch case. It must be used in for or while or do

while loop. If there is any looping statement in switch case then we can use continue.

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9 .

What is the output of the program in Turbo C (in DOS 16-bit OS)?

#include<stdio.h> int main() { char *s1; char far *s2; char huge *s3;

printf("%d, %d, %d\n", sizeof(s1), sizeof(s2), sizeof(s3)); return 0; } A.2, 4, 6 B. 4, 4, 2 C.2, 4, ₄ D.2, 2, ₂ Answer: Option C Explanation:

Any pointer size is 2 bytes. (only 16-bit offset) So, char *s1 = 2 bytes.

So, char far *s2; = 4 bytes. So, char huge *s3; = 4 bytes.

A far, huge pointer has two parts: a 16-bit segment value and a 16-bit offset value.

Since C is a compiler dependent language, it may give different output in ohter platforms. The above program works fine in Windows (TurboC), but error in Linux (GCC Compiler).

10

. In the following program add a statement in the function fun() such that address of a gets stored in j?

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int main() { int *j; void fun(int**); fun(&j); return 0; } void fun(int **k) { int a=10;

/* Add a statement here */ }

A.**k=a; B.k=&a;

C.*k=&a D.&k=*a

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11 .

What will be the output of the program ?

#include<stdio.h> int main() { FILE *ptr; char i; ptr = fopen("myfile.c", "r"); while((i=fgetc(ptr))!=NULL) printf("%c", i); return 0; }

A.Print the contents of file "myfile.c"

B.Print the contents of file "myfile.c" upto NULL character C.Infinite loop

D.Error in program

Answer: Option C Explanation:

The program will generate infinite loop. When an EOF is encountered fgetc() returns EOF. Instead of checking the condition for EOF we have checked it for NULL. so the program will generate infinite loop.

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12

. Can I increase the size of statically allocated array?_A.Yes _B.No

Answer: Option B

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13

. What will be the output of the program ?

#include<stdio.h> int main() { int arr[1]={10}; printf("%d\n", 0[arr]); return 0; } A.1 B.1₀ C.0 D.6 Answer: Option B Explanation:

Step 1: int arr[1]={10}; The variable arr[1] is declared as an integer array with size '2' and

it's first element is initialized to value '10'(means arr[0]=10)

Step 2: printf("%d\n", 0[arr]); It prints the first element value of the variable arr.

Hence the output of the program is 10.

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14

. When we mention the prototype of a function?_A.Defining _B.Declaring

C.Prototyping D.Calling

A function prototype in C or C++ is a declaration of a function that omits the function body but does specify the function's name, argument types and return type.

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While a function definition specifies what a function does, a function prototype can be thought of as specifying its interface.

15

. Which of the following statements should be used to obtain a remainder after dividing 3.14 by 2.1 ? A.rem = 3.14 % 2.1;

B.rem = modf(3.14, 2.1); C.rem = fmod(3.14, 2.1);

D.Remainder cannot be obtain in floating point division.

fmod(x,y) - Calculates x modulo y, the remainder of x/y.

This function is the same as the modulus operator. But fmod() performs floating point divisions. Example: #include <stdio.h> #include <math.h> int main () {

printf ("fmod of 3.14/2.1 is %lf\n", fmod (3.14,2.1) ); return 0;

}

Output:

fmod of 3.14/2.1 is 1.040000

16 .

#include<stdio.h>

#define MAX(a, b) (a > b ? a : b) int main()

{

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x = MAX(3+2, 2+7); printf("%d\n", x); return 0; } A.8 B.9 C.6 D.5 Answer: Option B Explanation:

The macro MAX(a, b) (a > b ? a : b) returns the biggest value of the given two numbers.

Step 1 : int x; The variable x is declared as an integer type. Step 2 : x = MAX(3+2, 2+7); becomes,

=> x = (3+2 > 2+7 ? 3+2 : 2+7) => x = (5 > 9 ? 5 : 9)

=> x = 9

Step 3 : printf("%d\n", x); It prints the value of variable x.

Hence the output of the program is 9.

17 .

#include<stdio.h>

#define JOIN(s1, s2) printf("%s=%s %s=%s \n", #s1, s1, #s2, s2); int main() { char *str1="India"; char *str2="BIX"; JOIN(str1, str2); return 0; }

A.str1=IndiaBIX str2=BIX B.str1=India str2=BIX

C.str1=India str2=IndiaBIX D.Error: in macro substitution

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18 .

Point out the error in the following code?

typedef struct { int data; NODEPTR link; }*NODEPTR; A.Error: in *NODEPTR

B.Error: typedef cannot be used until it is defined C.No error

D.None of above

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19 .

Point out the error in the program?

#include<stdio.h> int main() { struct emp { char name[20]; float sal; };

struct emp e[10]; int i;

for(i=0; i<=9; i++)

scanf("%s %f", e[i].name, &e[i].sal); return 0;

}

A.Error: invalid structure member

B.Error: Floating point formats not linked C.No error

D.None of above

At run time it will show an error then program will be terminated. Sample output: Turbo C (Windows)

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c:\>myprogram

Sample

12.123

scanf : floating point formats not linked Abnormal program termination

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20 .

#include<stdio.h> int main() { char str[] = "peace"; char *s = str; printf("%s\n", s++ +3); return 0; } A.peace B.eace C.ace D.ce Answer: Option D

1. Which of the following statements are correct about the below C-program?

{

int x = 10, y = 100%90, i; for(i=1; i<10; i++)

if(x != y);

printf("x = %d y = %d\n", x, y); return 0;

}

1 : The printf() function is called 10 times.

2 : The program will produce the output x = 10 y = 10 3 : The ; after the if(x!=y) will NOT produce an error. 4 : The program will not produce output.

A.1 B.2, ₃

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2 .

#include<stdio.h> int main() { int k, num=30; k = (num>5 ? (num <=10 ? 100 : 200): 500); printf("%d\n", num); return 0; } A.20₀ B.3₀ C.10₀ D.50₀ Answer: Option B Explanation:

Step 1: int k, num=30; here variable k and num are declared as an integer type and variable

num is initialized to '30'.

Step 2: k = (num>5 ? (num <=10 ? 100 : 200): 500); This statement does not affect the output

of the program. Because we are going to print the variable num in the next statement. So, we skip this statement.

Step 3: printf("%d\n", num); It prints the value of variable num '30' Step 3: Hence the output of the program is '30'

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3 .

Point out the error in the following program.

for(i=0; i<=9; i++)

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}

A.Suspicious pointer conversion

B.Floating point formats not linked (Run time error)

C.Cannot use scanf() for _structures

D.Strings cannot be nested inside structures

Compile and Run the above program in Turbo C:

C:\>myprogram.exe Sundar

2555.50

The program terminates abnormally at the time of entering the float value for e[i].sal.

Solution:

Just add the following function in your program. It will force the compiler to include required libraries for handling floating point linkages.

static void force_fpf() /* A dummy function */ {

float x, *y; /* Just declares two variables */ y = &x; /* Forces linkage of FP formats */ x = *y; /* Suppress warning message about x */ }

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4 .

The keyword used to transfer control from a function back to the calling function is

A.switch B.goto

C.go back D.return

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Example:

#include<stdio.h>

int add(int, int); /* Function prototype */ int main() { int a = 4, b = 3, c; c = add(a, b); printf("c = %d\n", c); return 0; }

int add(int a, int b) {

/* returns the value and control back to main() function */ return (a+b);

}

Output:

c = 7

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5

. Which of the following statements are correct about the function?

long fun(int num) {

int i; long f=1;

for(i=1; i<=num; i++) f = f * i;

return f; }

A.The function calculates the value of 1 raised to power num. B.The function calculates the square root of an integer

C.The function calculates the factorial value of an integer D.None of above

Yes, this function calculates and return the factorial value of an given integer num.

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6

. Which of the statements is correct about the program?

#include<stdio.h> int main() { float a=3.14; char *j; j = (char*)&a; printf("%d\n", *j); return 0; }

A.It prints ASCII value of the binary number present in the first byte of a float variable _a. B.It prints character equivalent of the binary number present in the first byte of a float _{variable a.} C.It will print 3

D.It will print a garbage _value

Answer: Option A

7 .

Will the program compile in Turbo C?

#include<stdio.h> int main() { int a=10, *j; void *k; j=k=&a; j++; k++; printf("%u %u\n", j, k); return 0; } A.Yes B.No Answer: Option B Explanation:

Error in statement k++. We cannot perform arithmetic on void pointers.

The following error will be displayed while compiling above program in TurboC. Compiling PROGRAM.C:

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Error PROGRAM.C 8: Size of the type is unknown or zero.

8 .

Which of the following statements are correct about an array? 1: The array int num[26]; can store 26 elements.

2: The expression num[1] designates the very first element in the array. 3: It is necessary to initialize the array at the time of declaration.

4: The declaration num[SIZE] is allowed if SIZE is a macro.

A.1 B.1,₄ C.2, 3 D. 2, 4 Answer: Option B Explanation:

1. The array int num[26]; can store 26 elements. This statement is true.

2. The expression num[1] designates the very first element in the array. This statement is false, because it designates the second element of the array.

3. It is necessary to initialize the array at the time of declaration. This statement is false.

4. The declaration num[SIZE] is allowed if SIZE is a macro. This statement is true, because the MACRO just replaces the symbol SIZE with given value.

Hence the statements '1' and '4' are correct statements.

9 .

The library function used to find the last occurrence of a character in a string is A.strnstr(

) B.laststr()

C.strrchr() D.strstr(₎

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Declaration: char *strrchr(const char *s, int c);

It scans a string s in the reverse direction, looking for a specific character c.

Example:

#include <string.h> #include <stdio.h> int main(void) {

char text[] = "I learn through IndiaBIX.com"; char *ptr, c = 'i';

ptr = strrchr(text, c); if (ptr)

printf("The position of '%c' is: %d\n", c, ptr-text); else

printf("The character was not found\n"); return 0;

}

Output:

The position of 'i' is: 19

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10 .

If char=1, int=4, and float=4 bytes size, What will be the output of the program ?

{

char ch = 'A';

printf("%d, %d, %d", sizeof(ch), sizeof('A'), sizeof(3.14f)); return 0; } A.1, 2, 4 B. 1, 4, 4 C.2, 2, ₄ D.2, 4, ₈ Answer: Option B Explanation:

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value 'A'.

Step 2:

printf("%d, %d, %d", sizeof(ch), sizeof('A'), sizeof(3.14));

The sizeof function returns the size of the given expression.

sizeof(ch) becomes sizeof(char). The size of char is 1 byte.

sizeof('A') becomes sizeof(65). The size of int is 4 bytes (as mentioned in the question). sizeof(3.14f). The size of float is 4 bytes.

Hence the output of the program is 1, 4, 4

11

#include<stdio.h> int main() { char str[] = "Nagpur"; str[0]='K'; printf("%s, ", str); str = "Kanpur"; printf("%s", str+1); return 0; }

A.Kagpur, Kanpur B.Nagpur, Kanpur

C.Kagpur, anpur D.Error

The statement str = "Kanpur"; generates the LVALUE required error. We have to use strcpy function to copy a string.

To remove error we have to change this statement str = "Kanpur"; to strcpy(str, "Kanpur"); The program prints the string "anpur"

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12 .

{

int i=4, j=8;

printf("%d, %d, %d\n", i|j&j|i, i|j&j|i, i^j); return 0; } A.12, 12, 12 B. 112, 1, 12 C.32, 1, ₁₂ D.-64, 1, ₁₂ Answer: Option A

13 .

Bit fields CANNOT be used in union.

A.True B.False

The following is the example program to explain "using bit fields inside an union".

#include<stdio.h> union Point

{

unsigned int x:4; unsigned int y:4; int res; }; int main() { union Point pt; pt.x = 2; pt.y = 3; pt.res = pt.y;

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return 0; }

// Output: The value of res = 3

14 .

Which of the following statement is correct about the program?

#include<stdio.h> int main() { FILE *fp; char ch; int i=1; fp = fopen("myfile.c", "r"); while((ch=getc(fp))!=EOF) { if(ch == '\n') i++; } fclose(fp); return 0; }

A.The code counts number of characters in the file B.The code counts number of words in the file C.The code counts number of blank lines in the file D.The code counts number of lines in the file

This program counts the number of lines in the file myfile.c by counting the character '\n' in that file.

15

. The first argument to be supplied at command-line must always be count of total arguments._A.True _B.False

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16

. What will be the output of the program?

{

char c=48; int i, mask=01; for(i=1; i<=5; i++) { printf("%c", c|mask); mask = mask<<1; } return 0; } A.1240 0 B. 1248 0 C.1250₀ D.1255₆ Answer: Option B

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17 .

What is the output of the program?

typedef struct data; {

int x; sdata *b; }sdata;

A.Error: Declaration missing ';' B.Error: in _typedef

C.No error D.None of above

since the type 'sdata' is not known at the point of declaring the structure

18

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A.varagrg._h B.stdlib.h

C.stdio.h D.stdarg.h

Answer: Option D

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19 .

Point out the error in the following program.

#include<stdio.h> #include<stdarg.h> void varfun(int n, ...); int main() { varfun(3, 7, -11.2, 0.66); return 0; } void varfun(int n, ...) { float *ptr; int num; va_start(ptr, n);

num = va_arg(ptr, int); printf("%d", num); }

A.Error: too many parameters

B.Error: invalid access to list member C.Error: ptr must be type of _{va_list}

D.No error

20 .

va_list is an array that holds information needed by va_arg and va_end

A.True B.False

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#include<stdio.h> int main() { int j=1; while(j <= 255) { printf("%c %d\n", j, j); j++; } return 0; }

A.Infinite times B.255 times

C.256 times D.254 times

The while(j <= 255) loop will get executed 255 times. The size short int(2 byte wide) does not affect the while() loop.

2 .

Which of the following errors would be reported by the compiler on compiling the program given below? #include<stdio.h> int main() { int a = 5; switch(a) { case 1: printf("First"); case 2: printf("Second"); case 3 + 2: printf("Third"); case 5: printf("Final"); break; } return 0; }

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B.Expression as in case 3 + 2 is not allowed. C.Duplicate case case _5:

D.No error will be reported.

Because, case 3 + 2: and case 5: have the same constant value 5.

3 .

Point out the error, if any in the program.

#include<stdio.h> int main() { int P = 10; switch(P) { case 10: printf("Case 1"); case 20: printf("Case 2"); break; case P: printf("Case 2"); break; } return 0; }

A.Error: No default value is specified

B.Error: Constant expression required at line case

P:

C.Error: There is no break statement in each case. D.No error will be reported.

The compiler will report the error "Constant expression required" in the line case P: . Because, variable names cannot be used with case statements.

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The case statements will accept only constant expression.

4 .

{

int i=2;

printf("%d, %d\n", ++i, ++i); return 0; } A.3, 4 B.4, ₃ C.4, ₄

D.Output may vary from compiler to compiler

The order of evaluation of arguments passed to a function call is unspecified.

Anyhow, we consider ++i, ++i are Right-to-Left associativity. The output of the program is 4, 3.

In TurboC, the output will be 4, 3. In GCC, the output will be 4, 4.

5 .

In the expression a=b=5 the order of Assignment is NOT decided by Associativity of operators

A.True B.False

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The equal to = operator has Right-to-Left Associativity. So it assigns b=5 then a=b.

6 .

What is the notation for following functions?

1. int f(int a, float b) { /* Some code */ } 2. int f(a, b) int a; float b; { /* Some code */ } A. 1. KR Notation 2. ANSI Notation B. 1. Pre ANSI C Notation 2. KR Notation C. 1. ANSI Notation 2. KR Notation D. 1. ANSI Notation 2. Pre ANSI Notation Answer: Option C Explanation:

KR Notation means Kernighan and Ritche Notation.

7

. How many times the program will print "IndiaBIX" ?

#include<stdio.h> int main() { printf("IndiaBIX"); main(); return 0; }

C.65535 times D.Till stack doesn't overflow

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Explanation:

A call stack or function stack is used for several related purposes, but the main reason for having one is to keep track of the point to which each active subroutine should return control when it finishes executing.

A stack overflow occurs when too much memory is used on the call stack.

Here function main() is called repeatedly and its return address is stored in the stack. After stack memory is full. It shows stack overflow error.

8 .

#include<stdio.h> #define SQR(x)(x*x) int main() { int a, b=3; a = SQR(b+2); printf("%d\n", a); return 0; } A.2 5 B. 1 1

C.Error D.Garbage value

The macro function SQR(x)(x*x) calculate the square of the given number 'x'. (Eg: 102₎

Step 1: int a, b=3; Here the variable a, b are declared as an integer type and the variable b is

initialized to 3.

Step 2: a = SQR(b+2); becomes,

=> a = b+2 * b+2; Here SQR(x) is replaced by macro to x*x . => a = 3+2 * 3+2;

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=> a = 11;

Step 3: printf("%d\n", a); It prints the value of variable 'a'.

Hence the output of the program is 11

9 .

A preprocessor directive is a message from programmer to the preprocessor.

A.True B.False

True, the programmer tells the compiler to include the preprocessor when compiling.

10 .

#include<stdio.h> int main() { char *p; p="hello"; printf("%s\n", *&*&p); return 0; } A.llo B.hello C.ello D.h Answer: Option B

11

. How will you free the allocated memory ?_{A.remove(var-name);} _{B.free(var-name);} C.delete(var-name); D.dalloc(var-name);

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12 .

In a file contains the line "I am a boy\r\n" then on reading this line into the array str using

fgets(). What will str contain?

A."I am a boy\r\n\0" B."I am a _boy\r\0" C."I am a

boy\n\0" D."I am a boy"

Declaration: char *fgets(char *s, int n, FILE *stream);

fgets reads characters from stream into the string s. It stops when it reads either n - 1

characters or a newline character, whichever comes first. Therefore, the string str contain "I am a boy\n\0"

13 .

Which files will get closed through the fclose() in the following program?

#include<stdio.h> int main() { FILE *fs, *ft, *fp; fp = fopen("A.C", "r"); fs = fopen("B.C", "r"); ft = fopen("C.C", "r"); fclose(fp, fs, ft); return 0; } A."A.C" "B.C" "C.C" B."B.C" "C.C" C."A.C" D.Error in _fclose()

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14 .

If the file 'source.txt' contains a line "Be my friend" which of the following will be the output of below program? #include<stdio.h> int main() { FILE *fs, *ft; char c[10]; fs = fopen("source.txt", "r"); c[0] = getc(fs); fseek(fs, 0, SEEK_END); fseek(fs, -3L, SEEK_CUR); fgets(c, 5, fs); puts(c); return 0; } A.friend B.frien C.end D.Error in fseek(); Answer: Option C Explanation:

The file source.txt contains "Be my friend".

fseek(fs, 0, SEEK_END); moves the file pointer to the end of the file.

fseek(fs, -3L, SEEK_CUR); moves the file pointer backward by 3 characters. fgets(c, 5, fs); read the file from the current position of the file pointer.

Hence, it contains the last 3 characters of "Be my friend". Therefore, it prints "end".

15 .

According to ANSI specifications which is the correct way of declaring main when it receives command-line arguments?

A.int main(int argc, char *argv[])

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C.

int main() {

int argc; char *argv; }

D.None of above

16 .

What will be the output of the program (myprog.c) given below if it is executed from the command line?

cmd> myprog one two three

/* myprog.c */ #include<stdio.h> #include<stdlib.h>

int main(int argc, char **argv) { printf("%s\n", *++argv); return 0; } A.myprog B.one C.tw_o D.three Answer: Option B

17 .

Point out the correct statement which correctly allocates memory dynamically for 2D array following program? #include<stdio.h> #include<stdlib.h> int main() { int *p, i, j;

/* Add statement here */ for(i=0; i<3; i++)

{ for(j=0; j<4; j++) { p[i*4+j] = i; printf("%d", p[i*4+j]); } }

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return 0; }

A.p = (int*) malloc(3, 4);

B.p = (int*) malloc(3*sizeof(int)); C.p = malloc(3*4*sizeof(int)); D.p = (int*) malloc(3*4*sizeof(int));

18 .

malloc() allocates memory from the heap and not from the stack.

A.True B.False

19

. Point out the error in the following program.

#include<stdio.h> #include<stdarg.h> void display(char *s, ...); int fun1(); int fun2(); int main() { int (*p1)(); int (*p2)(); p1 = fun1; p2 = fun2; display("IndiaBIX", p1, p2); return 0; } void display(char *s, ...) { int (*pp1)(); int (*pp2)(); va_list ptr; va_start(ptr, s); pp1 = va_arg(ptr, int(*)()); (*pp1)(); pp2 = va_arg(ptr, int(*)()); (*pp2)(); }

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int fun1() { printf("Hello"); } int fun2() { printf("Hi"); }

A.Error: invalid function display() call

B.Error: invalid va_start(ptr, _s);

C.Error: va_arg cannot extract function pointer from variable argument list. D.Error: Rvalue required for

t

20

. What do the following declaration signify?

int (*ptr)[30];

A.ptr is a pointer to an array of 30 integer pointers. B.ptr is a array of 30 integer function pointer. C.ptr is a array of 30 integer pointers.

D.ptr is a array 30 pointers.

1. Which statement will you add in the following program to work it correctly?

#include<stdio.h> int main() { printf("%f\n", log(36.0)); return 0; } A.#include<conio.h> B.#include<math.h> C.#include<stdlib.h> D.#include<dos.h> Answer: Option B

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Explanation:

math.h is a header file in the standard library of C programming language designed for basic

mathematical operations.

Declaration syntax: double log(double);

Learn more problems on : Floating Point Issues Discuss about this problem : Discuss in Forum

2 .

#include<stdio.h>

#define PRINT(i) printf("%d,",i) int main() { int x=2, y=3, z=4; PRINT(x); PRINT(y); PRINT(z); return 0; } A.2, 3, 4 B. 2, 2, 2 C.3, 3, ₃ D.4, 4, ₄ Answer: Option A Explanation:

The macro PRINT(i) print("%d,", i); prints the given variable value in an integer format.

Step 1: int x=2, y=3, z=4; The variable x, y, z are declared as an integer type and initialized to

2, 3, 4 respectively.

Step 2: PRINT(x); becomes printf("%d,",x). Hence it prints '2'. Step 3: PRINT(y); becomes printf("%d,",y). Hence it prints '3'. Step 4: PRINT(z); becomes printf("%d,",z). Hence it prints '4'.

Hence the output of the program is 2, 3, 4.

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3 .

What will be the output of the program assuming that the array begins at the location 1002 and size of an integer is 4 bytes?

{

int a[3][4] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 }; printf("%u, %u, %u\n", a[0]+1, *(a[0]+1), *(*(a+0)+1)); return 0; } A.448, 4, 4 B. 520, 2, 2 C.1006, 2, ₂ D.Error Answer: Option C

4 .

Which of the following statements correct about k used in the below statement?

char ****k;

A.k is a pointer to a pointer to a pointer to a char

B.k is a pointer to a pointer to a pointer to a pointer to a char C.k is a pointer to a char _pointer

D.k is a pointer to a pointer to a char

5 .

What does the following declaration mean?

int (*ptr)[10];

A.ptr is array of pointers to 10 integers B.ptr is a pointer to an array of 10 integers C.ptr is an array of 10 integers

D.ptr is an pointer to array

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6 .

What will be the output of the program in Turbo-C ?

{

int arr[5], i=-1, z; while(i<5)

arr[i]=++i; for(i=0; i<5; i++)

printf("%d, ", arr[i]); return 0; } A.1, 2, 3, 4, _5, B.-1, 0, 1, 2, 3, ₄ C.0, 1, 2, 3, 4, D. 0, -1, -2, -3, -4, Answer: Option C Explanation:

Since C is a compiler dependent language, it may give different outputs at different platforms. We have given the Turbo-C Compiler (under DOS) output.

Please try the above programs in Windows (Turbo-C Compiler) and Linux (GCC Compiler), you will understand the difference better.

7 .

What will be the output of the program in 16-bit platform (Turbo C under DOS) ?

{

printf("%d, %d, %d", sizeof(3.0f), sizeof('3'), sizeof(3.0)); return 0; } A.8, 1, 4 B. 4, 2, 8 C.4, 2, ₄ D.10, 3, ₄ Answer: Option B

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Explanation: Step 1:

printf("%d, %d, %d", sizeof(3.0f), sizeof('3'), sizeof(3.0));

The sizeof function returns the size of the given expression.

sizeof(3.0f) is a floating point constant. The size of float is 4 bytes sizeof('3') It converts '3' in to ASCII value.. The size of int is 2 bytes sizeof(3.0) is a double constant. The size of double is 8 bytes

Hence the output of the program is 4,2,8

Note: The above program may produce different output in other platform due to the platform dependency of C compiler.

In Turbo C, 4 2 8. But in GCC, the output will be 4 4 8.

8 .

for(i=0; i<=9; i++)

}

A.Error: invalid structure member

B.Error: Floating point formats not linked C.No error

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At run time it will show an error then program will be terminated. Sample output: Turbo C (Windows)

c:\>myprogram

Sample

12.123

9 .

A structure can contain similar or dissimilar elements

A.True B.False

10 .

A pointer union CANNOT be created

A.Yes B.No

11 .

What will be the output of the program if value 25 given to scanf()?

{

int i;

printf("%d\n", scanf("%d", &i)); return 0;

}

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C.1 D.5

The scanf function returns the number of input is given.

printf("%d\n", scanf("%d", &i)); The scanf function returns the value 1(one).

Therefore, the output of the program is '1'.

12

. Point out the error in the program?

#include<stdio.h> #include<stdlib.h> int main() { unsigned char; FILE *fp; fp=fopen("trial", "r"); if(!fp) {

printf("Unable to open file"); exit(1);

}

fclose(fp); return 0; }

A.Error: in unsigned char statement B.Error: unknown file _pointer

C.No error D.None of above

This program tries to open the file trial.txt in read mode. If file not exists or unable to read it prints "Unable to open file" and then terminate the program.

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13 .

What will be the output of the program (sample.c) given below if it is executed from the command line (turbo c under DOS)?

cmd> sample Good Morning

/* sample.c */ #include<stdio.h>

int main(int argc, char *argv[]) {

printf("%d %s", argc, argv[1]); return 0;

}

A.3 Good B.2 Good

C.Good Morning D.3 _Morning

14 .

What will be the output of the program (sample.c) given below if it is executed from the command line?

cmd> sample friday tuesday sunday

/* sample.c */ #include<stdio.h>

int main(int argc, char *argv[]) { printf("%c", *++argv[2] ); return 0; } A.s B.f C.u D.r Answer: Option C

15

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16 .

If the different command line arguments are supplied at different times would the output of the following program change?

#include<stdio.h>

int main(int argc, char **argv) { printf("%d\n", argv[argc]); return 0; } A.Yes B.No Answer: Option B

17

#include<stdio.h>

typedef struct error {int warning, err, exception;} ERROR; int main() { ERROR e; e.err=1; printf("%d\n", e.err); return 0; } A.0 B.1 C.2 D.Error Answer: Option B

18

{

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printf("%d\n", i++); return 0; } A.1 0 B. 1 1

C.No output D.Error: ++needs a value

This program will show an error "Cannot modify a const object".

Step 1: const int i=0; The constant variable 'i' is declared as an integer and initialized with

value of '0'(zero).

Step 2: printf("%d\n", i++); Here the variable 'i' is increemented by 1(one). This will create

an error "Cannot modify a const object". Because, we cannot modify a const variable.

Learn more problems on : Const

19 .

Which standard library function will you use to find the last occurance of a character in a string in C?

A.strnchar(₎ B.strchar(₎

C.strrchar(₎ D.strrchr()

strrchr() returns a pointer to the last occurrence of character in a string.

Example: #include <stdio.h> #include <string.h> int main() { char str[30] = "12345678910111213";

printf("The last position of '2' is %d.\n", strrchr(str, '2') - str);

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return 0; }

Output: The last position of '2' is 14.

Learn more problems on : Library Functions Discuss about this problem : Discuss in Forum

20 .

Data written into a file using fwrite() can be read back using fscanf()

A.True B.False

fwrite() - Unformatted write in to a file. fscanf() - Formatted read from a file.

1. How many times "IndiaBIX" is get printed?

#include<stdio.h> int main() { int x; for(x=-1; x<=10; x++) { if(x < 5) continue; else break; printf("IndiaBIX"); } return 0; }

C.0 times D.10 times

2 .

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{ int i=-3, j=2, k=0, m; m = ++i && ++j || ++k; printf("%d, %d, %d, %d\n", i, j, k, m); return 0; } A.1, 2, 0, 1 B. -3, 2, 0, 1 C.-2, 3, 0, ₁ D.2, 3, 1, ₁ Answer: Option C Explanation:

Step 1: int i=-3, j=2, k=0, m; here variable i, j, k, m are declared as an integer type and

variable i, j, k are initialized to -3, 2, 0 respectively.

Step 2: m = ++i && ++j || ++k;

becomes m = (-2 && 3) || ++k; becomes m = TRUE || ++k;.

(++k) is not executed because (-2 && 3) alone return TRUE.

Hence this statement becomes TRUE. So it returns '1'(one). Hence m=1.

Step 3: printf("%d, %d, %d, %d\n", i, j, k, m); In the previous step the value of i,j are

increemented by '1'(one).

Hence the output is "-2, 3, 0, 1".

3

#include<stdio.h>

int addmult(int ii, int jj) { int kk, ll; kk = ii + jj; ll = ii * jj; return (kk, ll); } int main() { int i=3, j=4, k, l; k = addmult(i, j); l = addmult(i, j); printf("%d, %d\n", k, l); return 0;

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} A.12, 12 B. 7, 7 C.7, ₁₂ D.12, ₇ Answer: Option A Explanation:

Step 1: int i=3, j=4, k, l; The variables i, j, k, l are declared as an integer type and variable i, j

are initialized to 3, 4 respectively.

The function addmult(i, j); accept 2 integer parameters.

Step 2: k = addmult(i, j); becomes k = addmult(3, 4)

In the function addmult(). The variable kk, ll are declared as an integer type int kk, ll;

kk = ii + jj; becomes kk = 3 + 4 Now the kk value is '7'. ll = ii * jj; becomes ll = 3 * 4 Now the ll value is '12'. return (kk, ll); It returns the value of variable ll only.

The value 12 is stored in variable 'k'.

Step 3: l = addmult(i, j); becomes l = addmult(3, 4)

kk = ii + jj; becomes kk = 3 + 4 Now the kk value is '7'. ll = ii * jj; becomes ll = 3 * 4 Now the ll value is '12'. return (kk, ll); It returns the value of variable ll only.

The value 12 is stored in variable 'l'.

Step 4: printf("%d, %d\n", k, l); It prints the value of k and l

Hence the output is "12, 12".

4 .

Will the following program print the message infinite number of times?

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#define INFINITELOOP while(1) int main() { INFINITELOOP printf("IndiaBIX"); return 0; } A.Yes B.No Answer: Option A Explanation:

Yes, the program prints "IndiaBIX" and runs infinitely.

The macro INFINITELOOP while(1) replaces the text 'INFINITELOOP' by 'while(1)' In the main function, while(1) satisfies the while condition and it prints "IndiaBIX". Then it comes to while(1) and the loop runs infinitely.

5

#include<stdio.h>

int *check(static int, static int); int main() { int *c; c = check(10, 20); printf("%d\n", c); return 0; }

int *check(static int i, static int j) { int *p, *q; p = &i; q = &j; if(i >= 45) return (p); else return (q); } A.1₀ B.2₀

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D.Error: cannot use static for function parameters

6 .

If the size of integer is 4bytes, What will be the output of the program?

{

int arr[] = {12, 13, 14, 15, 16};

printf("%d, %d, %d\n", sizeof(arr), sizeof(*arr), sizeof(arr[0])); return 0;

}

A.10, 2, ₄ B.20, 4, ₄

C.16, 2, ₂ D.20, 2, ₂

7 .

In the following program add a statement in the function fact() such that the factorial gets stored in j. #include<stdio.h> void fact(int*); int main() { int i=5; fact(&i); printf("%d\n", i); return 0; } void fact(int *j) { static int s=1; if(*j!=0) { s = s**j; *j = *j-1; fact(j);

/* Add a statement here */ }

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A.j=s; B.*j=s;

C.*j=&s; D.&j=s;

8 .

What will be the output of the program if the array begins at address 65486?

{

int arr[] = {12, 14, 15, 23, 45}; printf("%u, %u\n", arr, &arr); return 0; } A.65486, ₆₅₄₈₈ B.65486, ₆₅₄₈₆ C.65486, ₆₅₄₉₀ D.65486, ₆₅₄₈₇ Answer: Option B Explanation:

Step 1: int arr[] = {12, 14, 15, 23, 45}; The variable arr is declared as an integer array and

initialized.

Step 2: printf("%u, %u\n", arr, &arr); Here,

The base address of the array is 65486.

=> arr, &arr is pointing to the base address of the array arr. Hence the output of the program is 65486, 65486

9

{

int i;

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if(printf("%s", a))

printf("The string is empty\n"); else

printf("The string is not empty\n"); return 0;

}

A.The string is empty B.The string is not empty

C.No output D.0

The function printf() returns the number of charecters printed on the console.

Step 1: char a[] = "\0"; The variable a is declared as an array of characters and it initialized

with "\0". It denotes that the string is empty.

Step 2: if(printf("%s", a)) The printf() statement does not print anything, so it returns '0'(zero).

Hence the if condition is failed.

In the else part it prints "The string is not empty".

10 .

What will be the output of the following program in 16 bit platform (in Turbo C under DOS) ?

{

printf("%u %s\n", &"Hello", &"Hello"); return 0;

}

A.177 Hello B.Hello 177

C.Hello Hello D.Error

In printf("%u %s\n", &"Hello", &"Hello");.

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The %s format specifier tells the compiler to print the string "Hello".

Hence the output of the program is "177 Hello". (Note: 177 is memory address it may change.)

11 .

If a char is 1 byte wide, an integer is 2 bytes wide and a long integer is 4 bytes wide then will the following structure always occupy 7 bytes?

struct ex { char ch; int i; long int a; }; A.Yes B.No Answer: Option B Explanation:

A compiler may leave holes in structures by padding the first char in the structure with another byte just to ensures that the integer that follows is stored at an location. Also, there might be 2extra bytes after the integer to ensure that the long integer is stored at an address, which is multiple of 4. Such alignment is done by machines to improve the efficiency of accessing values.

12 .

Point out the error/warning in the program?

#include<stdio.h> int main() { unsigned char ch; FILE *fp; fp=fopen("trial", "r"); while((ch = getc(fp))!=EOF) printf("%c", ch); fclose(fp); return 0; }

A.Error: in unsigned char declaration B.Error: while statement

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C.No error

D.It prints all characters in file "trial"

Here, EOF is -1. As 'ch' is declared as unsigned char it cannot deal with any negative value.

13 .

What will be the output of the program

#include<stdio.h> void fun(int); int main(int argc) { printf("%d\n", argc); fun(argc); return 0; } void fun(int i) { if(i!=4) main(++i); } A.1 2 ₃ B.1 2 3 ₄ C.2 3 4 D.1 Answer: Option B

14 .

Which of the following statements are correct about the program?

{

unsigned int num; int i;

scanf("%u", &num); for(i=0; i<16; i++) {

printf("%d", (num<<i & 1<<15)?1:0); }

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return 0; }

A.It prints all even bits from

num

B.It prints all odd bits from _num C.It prints binary equivalent _num D.Error

If we give input 4, it will print 00000000 00000100 ; If we give input 3, it will print 00000000 00000011 ; If we give input 511, it will print 00000001 11111111 ;

Learn more problems on : Bitwise Operators Discuss about this problem : Discuss in Forum

15

#include<stdio.h> int fun(int **ptr); int main()

{

int i=10;

const int *ptr = &i; fun(&ptr); return 0; } int fun(int **ptr) { int j = 223; int *temp = &j;

printf("Before changing ptr = %5x\n", *ptr); const *ptr = temp; printf("After changing ptr = %5x\n", *ptr); return 0; } A.Address of i_{Address of j} B. 10 22 3

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D.Garbage value

Learn more problems on : Const

16 .

Can I increase the size of dynamically allocated array?

A.Yes B.No

Use realloc(variable_name, value);

17 .

It is necessary to call the macro va_end if va_start is called in the function.

A.Yes B.No

18 .

What do the following declaration signify?

void (*cmp)();

A.cmp is a pointer to an void function type. B.cmp is a void type pointer _function.

C.cmp is a function that return a void pointer. D.cmp is a pointer to a function which returns void .

19 .

What will be the output of the program (in Turbo C under DOS)?

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{

char huge *near *far *ptr1; char near *far *huge *ptr2; char far *huge *near *ptr3;

printf("%d, %d, %d\n", sizeof(ptr1), sizeof(ptr2), sizeof(ptr3)); return 0; } A.4, 4, 8 B. 2, 4, 4 C.4, 4, ₂ D.2, 4, ₈ Answer: Option C

20 .

#include<stdio.h> #include<stdlib.h> int main() { char *i = "55.555"; int result1 = 10; float result2 = 11.111; result1 = result1+atoi(i); result2 = result2+atof(i);

printf("%d, %f", result1, result2); return 0; } A.55, 55.555 B. 66, 66.666600 C.65, _66.666000 D.55, ₅₅ Answer: Option C Explanation:

Function atoi() converts the string to integer. Function atof() converts the string to float.

result1 = result1+atoi(i);

Here result1 = 10 + atoi(55.555); result1 = 10 + 55;

result1 = 65;

(55)

Here result2 = 11.111 + atof(55.555); result2 = 11.111 + 55.555000;

result2 = 66.666000;

So the output is "65, 66.666000" .

1. The modulus operator cannot be used with a long double.

A.True B.False

fmod(x,y) - Calculates x modulo y, the remainder of x/y.

This function is the same as the modulus operator. But fmod() performs floating point or long

double divisions.

2

{

int i=-3, j=2, k=0, m; m = ++i && ++j && ++k;

printf("%d, %d, %d, %d\n", i, j, k, m); return 0; } A.-2, 3, 1, ₁ B.2, 3, 1, ₂ C.1, 2, 3, 1 D. 3, 3, 1, 2 Answer: Option A Explanation:

Step 1: int i=-3, j=2, k=0, m; here variable i, j, k, m are declared as an integer type and

variable i, j, k are initialized to -3, 2, 0 respectively.

Step 2: m = ++i && ++j && ++k;

becomes m = -2 && 3 && 1;

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Hence m=1.

Step 3: printf("%d, %d, %d, %d\n", i, j, k, m); In the previous step the value of i,j,k are

increemented by '1'(one).

Hence the output is "-2, 3, 1, 1".

3 .

In a function two return statements should never occur.

A.Yes B.No

No, In a function two return statements can occur but not successively.

Example:

#include <stdio.h>

int mul(int, int); /* Function prototype */ int main() { int a = 0, b = 3, c; c = mul(a, b); printf("c = %d\n", c); return 0; }

/* Two return statements in the mul() function */ int mul(int a, int b)

{ if(a == 0 || b == 0) { return 0; } else { return (a * b); } } Output: c = 0

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4 .

It is necessary that a header files should have a .h extension?

A.Yes B.No

No, the header files have any kind of extension.

5 .

How many bytes are occupied by near, far and huge pointers (DOS)? A.near=2 far=4

huge=4 B.

near=4 far=8 huge=8 C.near=2 far=4 _huge=8 D.near=4 far=4 _huge=8

near=2, far=4 and huge=4 pointers exist only under DOS. Under windows and Linux every

pointers is 4 bytes long.

6 .

{

int x=30, *y, *z;

y=&x; /* Assume address of x is 500 and integer is 4 byte size */ z=y; *y++=*z++; x++; printf("x=%d, y=%d, z=%d\n", x, y, z); return 0; }

A.x=31, y=502, z=502 B.x=31, y=500, z=500 C.x=31, y=498, z=498 D.x=31, y=504, z=504

(58)

7 .

#include<stdio.h> int main() { void *vp; char ch=74, *cp="JACK"; int j=65; vp=&ch; printf("%c", *(char*)vp); vp=&j; printf("%c", *(int*)vp); vp=cp; printf("%s", (char*)vp+2); return 0; } A.JCK B.J65K C.JAK D.JACK Answer: Option D

8 .

Which of the statements is correct about the program?

#include<stdio.h> int main() { int arr[3][3] = {1, 2, 3, 4}; printf("%d\n", *(*(*(arr)))); return 0; }

A.Output: Garbage value B.Output: 1

C.Output: 3 D.Error: Invalid indirection

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. #include<stdio.h> #include<string.h> int main() { char str[] = "India\0\BIX\0"; printf("%s\n", str); return 0; } A.BIX B.India

C.India BIX D.India\0BIX

A string is a collection of characters terminated by '\0'.

Step 1: char str[] = "India\0\BIX\0"; The variable str is declared as an array of characters and

initialized with value "India"

Step 2: printf("%s\n", str); It prints the value of the str.

The output of the program is "India".

10 .

What will be the output of the program in Turbo C (under DOS)?

#include<stdio.h> int main() { struct emp { char *n; int age; };

struct emp e1 = {"Dravid", 23}; struct emp e2 = e1;

strupr(e2.n);

printf("%s\n", e1.n); return 0;

}

A.Error: Invalid structure assignment B.DRAVID

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D.No output

11 .

#include<stdio.h> int main() { struct a { float category:5; char scheme:4; };

printf("size=%d", sizeof(struct a)); return 0;

}

A.Error: invalid structure member in

printf

B.Error in this float category:5; statement C.No error

D.None of above

Bit field type must be signed int or unsigned int.

The char type: char scheme:4; is also a valid statement.

12

. Point out the error in the program?

#include<stdio.h> #include<string.h>

void modify(struct emp*); struct emp { char name[20]; int age; }; int main() {