C in 100 Seconds: calloc realloc — Zero Init and Resize | Episode 21

malloc gives you raw memory with whatever was there before. calloc gives you clean memory — every byte set to zero. realloc resizes an existing block without losing the data. calloc takes two arguments — the number of elements and the size of each. Five ints, all initialized to zero. realloc grows the array from five to eight, keeping the original values and adding room for more. Free the block when done. calloc for clean starts, realloc for growing — both end with free. Student code: https://github.com/GoCelesteAI/c-in-100-seconds/tree/main/episode21 What You'll Learn: • calloc — allocate and zero-initialize memory • Two arguments: count and size per element • realloc — resize an existing memory block • Original data preserved after realloc • Always free when done Next: Episode 22 — Memory Leaks #c #programming #100seconds #learnc #calloc #realloc #dynamicmemory #heap #resize #tutorial Tags c calloc, realloc c, dynamic memory c, resize array c, zero init memory, calloc vs malloc, c tutorial 2026, c beginner, 100 seconds, learn c, coding tutorial