sizeof Operators in C Programming

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In C, the sizeof operator is used to determine the size, in bytes, of a data type or a variable. It's often used in conjunction with arrays, structs, and other data types to calculate the memory space they occupy.

The syntax for the sizeof operator is:

sizeof(type);

sizeof(expression);

where type is a data type, and expression is any valid C expression.

Here are a few examples of how sizeof can be used:

To determine the size of a data type:

#include <stdio.h>

int main() {
    printf("Size of int: %zu bytes\n", sizeof(int));
    printf("Size of float: %zu bytes\n", sizeof(float));
    printf("Size of char: %zu bytes\n", sizeof(char));
    return 0;
}

Output:

Size of int: 4 bytes
Size of float: 4 bytes
Size of char: 1 bytes

To determine the size of a variable:

#include <stdio.h>

int main() {
    int arr[10];
    printf("Size of the array: %zu bytes\n", sizeof(arr));
    return 0;
}

Output:

Size of the array: 40 bytes

To determine the size of a struct:

#include <stdio.h>

struct Person {
    char name[20];
    int age;
};

int main() {
    printf("Size of struct Person: %zu bytes\n", sizeof(struct Person));
    return 0;
}

Output: