Frequently Asked Questions in Technical Round at MNCs like TCS, WIPRO, INFOSYS,..etc - 1

Predict the output or error(s) for the following:

1)

main()

{

static char names[5][20]={"pascal","ada","cobol","fortran","perl"};

int i;

char *t;

t=names[3];

names[3]=names[4];

names[4]=t;

for (i=0;i<=4;i++)

printf("%s",names[i]);

}

Answer:

Compiler error: Lvalue required in function main

Explanation:

Array names are pointer constants. So it cannot be modified.

2)

void main()

{

int i=5;

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

}

Answer:

Output Cannot be predicted  exactly.

Explanation:

Side effects are involved in the evaluation of   i.

3)

void main()

{

int i=5;

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

}

Answer:

Compiler Error

Explanation:

The expression i+++++i is parsed as i ++ ++ + i which is an illegal combination of operators.

4)

#include<stdio.h>

main()

{

int i=1,j=2;

switch(i)

 {

 case 1:  printf("GOOD");

break;

case j:  printf("BAD");

break;

}

}

Answer:

Compiler Error: Constant expression required in function main.

Explanation:

The case statement can have only constant expressions (this implies that we cannot use variable names directly so an error).

 Note:

Enumerated types can be used in case statements.