Labels
Both continue
and break
can optionally take a label argument which is used
to break out of nested loops:
fn main() { let s = [[5, 6, 7], [8, 9, 10], [21, 15, 32]]; let mut elements_searched = 0; let target_value = 10; 'outer: for i in 0..=2 { for j in 0..=2 { elements_searched += 1; if s[i][j] == target_value { break 'outer; } } } print!("elements searched: {elements_searched}"); }
- Note that
loop
is the only looping construct which returns a non-trivial value. This is because it's guaranteed to be entered at least once (unlikewhile
andfor
loops).