ruby - Ruby 什么时候需要 do 关键字？

Question

例如，以下代码中是否存在 do 是否会影响程序的行为？

while true do
    puts "Hi"
    break
end

while true
    puts "Hi"
    break
end

Answer 1

根据 The Ruby Programming Language本书第 5.2.1 节:

The do keyword in a while or until loop is like the then keyword in anif statement: it may be omitted altogether as long as a newline (orsemicolon) appears between the loop condition and the loop body.

所以，不，它不会改变行为，它只是可选语法。