if and else

Expressions

An if block returns a value when both branches produce the same type. Assign the whole if expression directly to a binding:

let n = 7; let label = if n > 5 { "big" } else { "small" };

Chains

Chain else if to test several ranges in order. Only the first true branch runs, so order from narrow to wide:

let score = 85; let grade = if score >= 90 { "A" } else if score >= 60 { "B" } else { "C" };

Nesting vs guards

Deep nesting hides the main path under many levels. Return early on bad input so the main logic stays flat:

fn check(age: u32) -> &str { if age < 18 { return "young"; } "adult" }

Prefer match preview

When branches test the same value against many patterns, match reads cleaner than long else if chains. The next lesson covers it in full:

let n = 2; let text = match n { 1 => "one", _ => "other", };

Next: match

Article author: Arthur Isaev