Explore topic-wise MCQs in Engineering.

Every C program will contain at least one preprocessor directive.

Preprocessor directive #ifdef .. #else ... #endif is used for conditional compilation.

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

/* sample.c */
#include<stdio.h>
#include<dos.h> int main(int arc, char *arv[])
{ int i; for(i=1; i<_argc; i++) printf("%s ", _argv[i]); return 0;
}

Macros with arguments are allowed

Which of the following statements correctly assigns 12 to month using pointer variable pdt?

#include<stdio.h> struct date { int day; int month; int year; };
int main()
{ struct date d; struct date *pdt; pdt = &d; return 0;
}

A union cannot be nested in a structure

Bit fields CANNOT be used in union.

one of elements of a structure can be a pointer to the same structure.

A structure can be nested inside another structure.

Point out the error in the program?

typedef struct data mystruct;
struct data
{ int x; mystruct *b;
};

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;
}

What will be the output of the program ?

#include<stdio.h> int main()
{ union a { int i; char ch[2]; }; union a u; u.ch[0]=3; u.ch[1]=2; printf("%d, %d, %d n", u.ch[0], u.ch[1], u.i); return 0;
}

What will be the output of the program ?

#include<stdio.h> int main()
{ struct value { int bit1:1; int bit3:4; int bit4:4; }bit={1, 2, 13}; printf("%d, %d, %d n", bit.bit1, bit.bit3, bit.bit4); return 0;
}

What will be the output of the program ?

#include<stdio.h> int main() { enum days {MON=-1, TUE, WED=6, THU, FRI, SAT}; printf("%d, %d, %d, %d, %d, %d n", MON, TUE, WED, THU, FRI, SAT); return 0; } 

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

#include<stdio.h> int main()
{ struct value { int bit1:1; int bit3:4; int bit4:4; }bit; printf("%d n", sizeof(bit)); return 0;
}

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> int main(int argc, char **argv)
{ printf("%c n", **++argv); return 0;
}

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;
}

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;
}

What will be the output of the program

#include<stdio.h>
void fun(int); int main(int argc)
{ printf("%d ", argc); fun(argc); return 0;
}
void fun(int i)
{ if(i!=4) main(++i);
}

What will be the output of the program ?

#include<stdio.h>
#include<string.h> int main()
{ int i, n; char *x="Alice"; n = strlen(x); *x = x[n]; for(i=0; i<=n; i++) { printf("%s ", x); x++; } printf(" n", x); return 0;
}

Macro calls and function calls work exactly similarly.

Every time we supply new set of values to the program at command prompt, we need to recompile the program.

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

#include<stdio.h> int main()
{ int arr[] = {12, 13, 14, 15, 16}; printf("%d, %d, %d n", sizeof(arr), sizeof(*arr), sizeof(arr[0])); return 0;
}

What will be the output of the program?

#include<stdio.h> #define SWAP(a, b) int t; t=a, a=b, b=t; int main() { int a=10, b=12; SWAP(a, b); printf("a = %d, b = %d n", a, b); return 0; } 

What will be the output of the program?

#include<stdio.h>
#define PRINT(int) printf("int=%d, ", int); int main()
{ int x=2, y=3, z=4; PRINT(x); PRINT(y); PRINT(z); return 0;
}

What will be the output of the program?

#include<stdio.h>
#define FUN(i, j) i##j int main()
{ int va1=10; int va12=20; printf("%d n", FUN(va1, 2)); return 0;
}

What will be the output of the program?

#include<stdio.h>
#define MAX(a, b) (a > b ? a : b) int main()
{ int x; x = MAX(3+2, 2+7); printf("%d n", x); return 0;
}

What will be the output of the program ?

#include<stdio.h> int main()
{ char str1[] = "India"; char str2[] = "BIX"; char *s1 = str1, *s2=str2; while(*s1++ = *s2++) printf("%s", str1); printf(" n"); return 0;
}

What will be the output of the program assuming that the array begins at location 1002?

#include<stdio.h> int main() { int a[2][3][4] = { {1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 1, 2}, {2, 1, 4, 7, 6, 7, 8, 9, 0, 0, 0, 0} }; printf("%u, %u, %u, %d n", a, *a, **a, ***a); return 0; } 

What will be the output of the program ?

#include<stdio.h> int main()
{ char str[] = "peace"; char *s = str; printf("%s n", s++ +3); return 0;
}

What will be the output of the program ?

#include<stdio.h>
power(int**);
int main()
{ int a=5, *aa; /* Address of 'a' is 1000 */ aa = &a; a = power(&aa); printf("%d n", a); return 0;
}
power(int **ptr)
{ int b; b = **ptr***ptr; return (b);
}

What will be the output of the program ?

#include<stdio.h> int main()
{ printf("%c n", 7["IndiaBIX"]); return 0;
}

What will be the output of the program ?

#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);
}

What will be the output of the program ?

#include<stdio.h> int main()
{ char *str; str = "%s"; printf(str, "K n"); return 0;
}

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

#include<stdio.h> #define INFINITELOOP while(1) int main() { INFINITELOOP printf("IndiaBIX"); return 0; } 

Will it result in to an error if a header file is included twice?

What will be the output of the program?

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

What will be the output of the program if the size of pointer is 4-bytes?

#include<stdio.h> int main()
{ printf("%d, %d n", sizeof(NULL), sizeof("")); return 0;
}

What will be the output of the program ?

#include<stdio.h> int main()
{ char *p; p="hello"; printf("%s n", *&amp*&p); return 0;
}

What will be the output of the program?

#include<stdio.h> int main() { int arr[2][2][2] = {10, 2, 3, 4, 5, 6, 7, 8}; int *p, *q; p = &arr[1][1][1]; q = (int*) arr; printf("%d, %d n", *p, *q); return 0; } 

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?

#include<stdio.h> int main() { 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; } 

Even if integer/float arguments are supplied at command prompt they are treated as strings.

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

Which of the following is TRUE about argv?

What will be the output of the program?

#include<stdio.h>
#define CUBE(x) (x*x*x) int main()
{ int a, b=3; a = CUBE(b++); printf("%d, %d n", a, b); return 0;
}

Point out the error in the program

#include<stdio.h>
#define SI(p, n, r) float si; si=p*n*r/100;
int main()
{ float p=2500, r=3.5; int n=3; SI(p, n, r); SI(1500, 2, 2.5); return 0;
}

What will be the output of the program?

#include<stdio.h> #define MAN(x, y) ((x)>(y)) ? (x):(y); int main() { int i=10, j=5, k=0; k = MAN(++i, j++); printf("%d, %d, %d n", i, j, k); return 0; } 

What will be the output of the program?

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

What will be the output of the program?

#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 text stream is an ordered sequence of characters composed into lines, each line consisting of zero or more characters plus a terminating new-line character.