C Aptitude: Practice Questions

Practice Questions: Predict the output of the following programs.

1.)main()

{

char a=3D 'A';

if( (a=3D=3D'Z')||( (a=3D'L')&&( a=3D=3D'A')))

a=3Da;

printf("%c",a);=20

printf(" Nothing ");

}

2.)main()

{

            static int a[5] ={2,4,6,8,10};

            int i,b=5;

            for(i=0; i< 5;i++)

            {

                        f(a[i],&b);

                        printf("%d %d\n",a[i],b);

            }

}

f(x,y)

int x,*y;

{

            x=*(y)+=2;

}

main()

{

printf("hello");

fork();

}

3. main()

{

char as[] = "\\0\0";

int i = 0;

do{

switch( as[i++]){

case '\\' : printf("A");

break;

case 0 : printf("B");

break;

default : printf("C");

break;

}

}

while(i<3)

}

4. main()

{=20

int a;

a = (1,45,012);

printf("%d", a);

}

5. main()

{

int i = 10;

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

}

6. #include<stdio.h>

main()

{

int *p, *c, i;

i = 5;

p = (int*) (malloc(sizeof(i)));

printf("\n%d",*p);

*p = 10;

printf("\n%d %d",i,*p);

c = (int*) calloc(2);

printf("\n%d\n",*c);

}

7. #include<stdio.h>

main()

{

int arr[3][3] ={1,2,3,

4,5,6,

7,8,9};

int i,j;

for (j=2;j>=0;j--){

for(i=2;i>=0;i--){

printf("\n%d",*(*(arr+i)+j));

printf("\n TATATATA");

}

}

}

8. main()

{

int i = 5, j=10;

abc(&i,&j);

printf("%d..%d",i,j);

}

abc(int *i, int *j)

{

*i = *i + *j;

*j = *i - *j;

*i = *i - *j;

}

9. #define PRINT(int) printf( "int = %d ", int)

main()

{

int x=03,y=02,z=01;

PRINT (x | y & ~z);

PRINT (x & y && z);

PRINT (x ^ y & ~z);

}

10. main()

{

unsigned int m[] = { 0x01,0x02, 0x04, 0x08,0x10, 0x20, 0x40, 0x80};

unsigned int n,i;

scanf("%d",&n);

for(i=0;i<=7;i++)

{ if (n& m[i])

printf("\nyes");

else=20

printf("\nno");

}

}

11. main()

{

int a,b=2,c;

int *pointer;

c = 3;

pointer = &c;

a = c/*pointer;=20

b = c /* assigning 3 to b*/;

printf("a = %d; b = %d", a,b);

}