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C Memory Management Example

📌 C Memory Management Example (Complete Program)

Here is a full practical example demonstrating malloc, calloc, realloc, and free all in one program.

✅ Full Example: Dynamic Array with Memory Operations

#include <stdio.h>

#include <stdlib.h>
int main() {

    int *arr;

    int n;
    // Step 1: Ask user for the size

    printf("Enter number of elements: ");

    scanf("%d", &n);
    // Step 2: Allocate memory using malloc

    arr = (int *)malloc(n * sizeof(int));
    if (arr == NULL) {

        printf("Memory allocation failed!\n");

        return 1;

    }
    printf("\nMemory allocated using malloc.\n");
    // Step 3: Take user input

    printf("Enter %d elements:\n", n);

    for (int i = 0; i < n; i++) {

        scanf("%d", &arr[i]);

    }
    // Step 4: Display values

    printf("\nValues stored in array:\n");

    for (int i = 0; i < n; i++) {

        printf("%d ", arr[i]);

    }
    // Step 5: Increase memory using realloc

    int newSize;

    printf("\n\nEnter new size (larger than previous): ");

    scanf("%d", &newSize);
    arr = (int *)realloc(arr, newSize * sizeof(int));
    if (arr == NULL) {

        printf("Memory reallocation failed!\n");

        return 1;

    }
    printf("\nMemory reallocated using realloc.\n");
    // Step 6: Initialize new values (if size increased)

    for (int i = n; i < newSize; i++) {

        arr[i] = 0;

    }
    // Step 7: Display updated array

    printf("\nUpdated array values:\n");

    for (int i = 0; i < newSize; i++) {

        printf("%d ", arr[i]);

    }
    // Step 8: Free allocated memory

    free(arr);

    printf("\n\nMemory freed successfully.\n");

return 0; }

🧠 What This Program Demonstrates

Function	Purpose
`malloc()`	Allocates memory without initializing values
`realloc()`	Resizes previously allocated memory
`free()`	Releases allocated memory

📌 Output Example

🚀 Key Best Practices

✔ Always check if memory allocation succeeded (ptr != NULL)
✔ Initialize memory when needed
✔ Always free memory when finished to prevent memory leaks
✔ Use realloc() only on dynamically allocated memory

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Sanjit Sinha — Web Developer | PHP • Laravel • CodeIgniter • MySQL • Bootstrap Founder, CodeCapsule — Student projects & practical coding guides. Email: info@codecapsule.in • Website: CodeCapsule.in

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