JavaScript CoffeeScript 中 switch-when 语句编译成 JavaScript 时为什么要用 switch (false) 的原因 在 CoffeeScript 指南的 switch 语句说明中,指明了 Switch statements can also be used without a control expression, turning them in to a cleaner alternative to if/else chains. score = 76 grade = switch when score < 60 then 'F' when score < 70 then 'D' when