Memory Management in C

Dynamic Memory Management allows programs to allocate memory during runtime using functions like malloc(), calloc(), realloc(), and free(). It is useful when the amount of memory needed is not known in advance.

Why Use Dynamic Memory?

• Efficient use of memory
• Allocate memory only when needed
• Useful for large data structures
• Flexible program design

Basic malloc / free Example

#include <stdio.h>
#include <stdlib.h>

int main() {
    int *ptr = (int*) malloc(sizeof(int));

    if (ptr == NULL) {
        printf("Memory allocation failed");
        return 1;
    }

    *ptr = 5;
    printf("%d", *ptr);

    free(ptr);
    return 0;
}

Output

Other Memory Functions

• calloc() – Allocates multiple blocks and initializes to 0
• realloc() – Resizes previously allocated memory
• free() – Releases allocated memory

Common Mistakes

• Forgetting to call free() (memory leak)
• Using memory after freeing it
• Not checking if malloc() returned NULL