C in 100 Seconds: Pass by Reference — Pointers as Parameters | Episode 19

C passes everything by value — the function gets a copy, not the original. A swap function that takes plain ints looks right but changes nothing. Pass pointers instead, and the function can reach the caller's variables through dereferencing. no_swap copies the values — x and y stay the same. swap takes addresses with ampersand and dereferences with star — x and y actually flip. Pointers let functions reach outside themselves. Student code: https://github.com/GoCelesteAI/c-in-100-seconds/tree/main/episode19 What You'll Learn: • C passes by value — functions get copies • Pointers as parameters — int *a instead of int a • Ampersand passes the address — swap(&x, &y) • Star dereferences — *a reads/writes the original • The classic swap demo: why it fails and how to fix it Next: Episode 20 — malloc and free #c #programming #100seconds #learnc #passbyreference #pointers #swap #dereference #tutorial Tags c pass by reference, pointers c, swap function c, pass by value vs reference, dereference c, ampersand c, c tutorial 2026, c beginner, 100 seconds, learn c, coding tutorial