Making Decisions
8 min · C
Run different code depending on whether something is true.
Enemy 1 of 5
if / else and comparison operators
An if statement lets your program choose between two paths. The condition inside ( ) is checked, and if it evaluates to true (in C, any non-zero value counts as true, and 0 counts as false), the { } block right after runs; otherwise it's skipped.
An else attached to that if provides the "otherwise" branch, running only when the if's condition was false. Together, if/else let a program make a decision instead of always doing the exact same thing every run.
Comparisons use > , < , >= , <= , == (equal to), and != (not equal to). Because C treats 0 as false and everything else as true, a very common beginner bug is writing if (x = 5) (a single = , which assigns 5 to x and is always true) when you meant if (x == 5) (a double ==, which actually compares). Watch for this — it's one of C's most infamous gotchas.
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