sizeof() operator in C

sizeof() operator is a unary operator used to find the size of the arrays or the size of a variable or size of structures in terms of bytes. If we use sizeof(variable), it returns the size taken by it in terms of bytes.

Syntax:

sizeof(variable_name);

Let us the application of the sizeof operator in the following example.

Example:

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

This program returns the output as

• 2
• 4

This is because, the variable a is of int type, hence it takes 2 bytes.

And the array b is of int type and the array size is 2. Hence it takes 4 bytes.