What is the purpose of sizeof() operator in C?

Question

What is the purpose of the sizeof() operator and how to use it?

Answer 1

In C language, the sizeof() operator is used to determine the size of a variable in bytes.

Here is an example to show how to use this operator in your program:

#include <stdio.h>

int main() {

    int num;

    float f;

    char c;

    char name[10];

    printf("Size of int: %lu bytes\n", sizeof(num));

    printf("Size of float: %lu bytes\n", sizeof(f));

    printf("Size of char: %lu bytes\n", sizeof(c));

    printf("Size of array: %lu bytes\n", sizeof(name));

    return 0;

}

The above code returns the following output:

Size of int: 4 bytes

Size of float: 4 bytes

Size of char: 1 bytes

Size of array: 10 bytes