The sizeof Operator in C.

By Shakib Ansari | Date: Mon, Mar 31, 2025

The sizeof operator ek compile time operator hai, ye tab use hota hai jab programmer ko kisi variable or data type ki number of bytes chahiye hoti hai. Ye kisi operand ke sath use hota hai. Wo operand ek variable, constant, ya ek data type qualifier ho sakta hai.

Example:

m = sizeof(sum);

n = sizeof(long int);

k = sizeof(235L);

The sizeof operator normally kisi array and structure ki lengths ko determine karte hai jab iska size programmer ko pata nhi hota hai. Iska use variables ko dynamically memory space allocate karne ke liye bhi hota hai during the execution of a progdyram.

C Code:

#include <stdio.h>

int main(int argc, char const *argv[])
{
    int num = 10;
    int sizeOfNum = sizeof(num);
    printf("Size of Number: %d", sizeOfNum);
    return 0;
}
Output: Size of Number: 4

Yaha par int ka size 4 bytes hai because of 64-bit Machine

Explanation:

  1. int num = 10; num ek variable jisko value 10 assign hai.
  2. int sizeOfNum = sizeof(num) sizeOfNum ek variable jise hamne int data type ka size assign kar diya using the sizeof operator.
  3. sizeof(num) sizeof operator mein hamne num variable ko pass kar diya hai jo ki num variable ke size ko return kar dega in bytes.
  4. printf("Size of Number: %d", sizeOfNum); Ek statement hai jo ki sizeOfNum ki value ko console par print karega.

Conclusion: sizeof operator ek bahut hi important operator hota hai especially jab ham variables ko dynamically memory allocate karte hai kiuki us situation mein ek programmer ko pta hona chahiye ki kisi variable ko kitni bytes ki need hai.

About the Author

Hi, I'm Shakib Ansari, Founder and CEO of BeyondMan. I'm a highly adaptive developer who quickly learns new programming languages and delivers innovative solutions with passion and precision.

Shakib Ansari
Programming

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