Making Decisions
7 min · PHP
Run different code depending on whether something is true.
Enemy 1 of 5
if / else and comparison operators
Real programs need to behave differently depending on the situation, and if is the tool that makes that possible. An if statement evaluates a condition — an expression that's either true or false — and only runs the code in its { } block when that condition is true. Pair it with an else block to provide a fallback for every other case.
Conditions are built with comparison operators: > (greater than), < (less than), >= and <= (greater/less than or equal to), and == (equal to). Notice that's a double equals sign — a single = is assignment (storing a value), while == is comparison (asking a question). Mixing the two up is one of the most common bugs in almost every C-family language, PHP included, so it's worth burning into memory early: one = sets a value, two == asks if two things are equal.
PHP also has a stricter === operator, which checks that both the value AND the type match (so "5" == 5 is true, but "5" === 5 is false because one's a string and the other's an integer). Beginners can stick with == for now, but it's good to know === exists once type-related bugs start showing up.
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