Technical Sample Questions : C |  C++ |  Oracle |  Java | Unix |  Operating Systems |  Data Structure

Sample Technical Questions

C Sample Question

136. main()
     {
     		int i=4,j=7;
     	j = j || i++ && printf("YOU CAN");
     		printf("%d %d", i, j);
     }

     Answer:

     4 1

     Explanation:

     The boolean expression needs to be evaluated only till the truth value of the expression is not known. j is not equal to zero itself means that the expression's truth value is 1. Because it is followed by || and true || (anything) => true where (anything) will not be evaluated. So the remaining expression is not evaluated and so the value of i remains the same. Similarly when && operator is involved in an expression, when any of the operands become false, the whole expression's truth value becomes false and hence the remaining expression will not be evaluated.
     false && (anything) => false where (anything) will not be evaluated.

137. main()
     {
     		register int a=2;
     	printf("Address of a = %d",&a);
     		printf("Value of a   = %d",a);
     }

     Answer:

     Compier Error: '&' on register variable
     Rule to Remember:
     & (address of ) operator cannot be applied on register variables.

138. main()
     {
     		float i=1.5;
     	switch(i)
     		{
     		case 1: printf("1");
     			case 2: printf("2");
     			default : printf("0");
     	}
     }

     Answer: Compiler Error: switch expression not integral

     Explanation: Switch statements can be applied only to integral types.

139. main()
     {	
     		extern i;
     	printf("%d\n",i);
     		{
     			int i=20;
     		printf("%d\n",i);
     		}
     }

     Answer:

     Linker Error : Unresolved external symbol i

     Explanation:

     The identifier i is available in the inner block and so using extern has no use in resolving it.

140. main()
     {
     		int a=2,*f1,*f2;
     	f1=f2=&a;
     		*f2+=*f2+=a+=2.5;
     	printf("\n%d %d %d",a,*f1,*f2);
     }

     Answer:

     16 16 16

     Explanation:

     f1 and f2 both refer to the same memory location a. So changes through f1 and f2 ultimately affects only the value of a.

C Sample Question Number : 1-3 | 4-7 | 8-11 | 12-16 | 17-21 | 22-25 | 26-30 | 31-35 | 36-40 | 41-45 | 46-48 | 49-52 | 53-59 | 60-64 | 65-69 | 70-74 | 75-79 | 80-83 | 84-87 | 88-91 | 92-95 | 96-100 | 101-105 | 106-110 | 111-115 | 116-120 | 121-125 | 126-130 | 131-135 | 136-140 | 141-145 | 146-150