C interview questions and answers

C interview questions and answers

1)What does a static variable mean?

Ans:A static variable is a special variable that is stored in the data segment unlike the default automatic variable that is stored in stack. A static variable can be initialised by using keyword static before variable name.

2)What is a pointer?

Ans:A pointer is a special variable in C language meant just to store address of any other variable or function. Pointer variables unlike ordinary variables cannot be operated with all the arithmetic operations such as '*','%' operators. It follows a special arithmetic called as pointer arithmetic.

3)What is a structure?

Ans:A structure is a collection of pre-defined data types to create a user-defined data type.


4)How to print below pattern?

1
2 3
4 5 6
7 8 9 10

Program:

#include

main() {

int i, j, ctr = 1;

for (i = 1; i < 5; i++) {

for (j = 1; j <= i; j++)

printf("%2d ", ctr++);

printf("\n");

}

}


5)How to swap two numbers using bitwise operators?

Program:

#include

main() {

int i = 65;

int k = 120;

printf("\n value of i=%d k=%d before swapping", i, k);

i = i ^ k;

k = i ^ k;

i = i ^ k;

printf("\n value of i=%d k=%d after swapping", i, k);

}