Dynamic Memory Allocation

Request memory at run time with malloc/calloc/realloc and give it back with free.

Intermediate

#include <stdlib.h>

int *buf = malloc(100 * sizeof *buf);   // uninitialised
if (buf == NULL) { /* out of memory */ }
int *zeros = calloc(100, sizeof *zeros); // zero-filled
buf = realloc(buf, 200 * sizeof *buf);   // grow (check the result!)
free(buf);
free(zeros);

Memory comes from the heap. On small microcontrollers, dynamic allocation is often avoided entirely because the heap can fragment and run out unpredictably — static buffers are safer.

Sub-topics (1)

Memory Leaks

Memory that is allocated but never freed — it slowly exhausts the heap.

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Sub-topics (1)

Memory Leaks

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