It is ambiguous when the coder intended to return directly without returning any value like so: while (word = getNextWord()) { doSomething(word)

It is ambiguous when the coder intended to return directly without returning any value like so: while (word = getNextWord()) { doSomething(word) if (i > limit) return i++ } Sure, this can be written better but a semi-colon after "return" makes it less ambiguous.