Blog / Go Language Spec

Break statements with labels

August 8, 2024

Break statements

…

If there is a label, it must be that of an enclosing “for”, “switch”, or “select” statement, and that is the one whose execution terminates.

In other words, you can’t break to a label that labels a more deeply nested for, switch or select statement, or to one that’s completely unrelated.

But that’s only intuitive, right?

OuterLoop:
	for i = 0; i < n; i++ {
		for j = 0; j < m; j++ {
			switch a[i][j] {
			case nil:
				state = Error
				break OuterLoop
			case item:
				state = Found
				break OuterLoop
			}
		}
	}

Speaking of labels, did you know that you can have blank labels? But that you can’t jump to them? Which, of course, raises the question: why have them at all!

_:  // A blank label. Can't do anything with it. Other than look at it, I guess

I did a video about some esoteric blank label bugs in Go and in golangci-lint, if you’re interested in random silly trivia.

Quotes from The Go Programming Language Specification Language version go1.22 (Feb 6, 2024)

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