compound statements
a block is a sequence of statements delimited by curly brackets (braces) that defines a scope
compound statements that control flow:
- if (EXPR) BLOCK
- if (EXPR) BLOCK else BLOCK
- if (EXPR) BLOCK elsif (EXPR) BLOCK ... else BLOCK
- LABEL while (EXPR) BLOCK
- LABEL while (EXPR) BLOCK continue BLOCK
- LABEL for (EXPR; EXPR; EXPR) BLOCK
- LABEL foreach VAR (LIST) BLOCK
- loop control via next, last, and redo
if ($model == 3000) { $os = 'mpe' };