javascript - 是否可以在 JavaScript 中添加 case 到 switch 语句？

Question

我的问题分为三个问题:

1.这可能吗？

2.如果可以的话可以用默认值吗？

3.或者可以在 switch 语句之外执行此操作吗？

问题 2 的示例:

switch(stuff) {
    case 'something':
        some event;
        break;
    case 'the case that could be add by the default element':
        some event that could happen only after the code was executed
    default:
        magic code that would add another case element
}

问题 3 的示例:

switch(stuff) {
    case 'something':
        some event;
        break;
    case 'the case that could be add by the magic code':
        some event that could happen only after the code was executed
    default:
        some default event
}

magic code that would be executed after the switch and that would add a case

Answer 1

您无法真正编写 JavaScript 代码以使其能够修改自身，但您可以编写一个 switch 语句，以便最初忽略某些情况，然后稍后“打开”:

var enableCase = false;

switch(true) {
    case stuff === 'something':
        // some code;
        break;
    case enableCase && stuff === 'the case not initially enabled':
        // some code
        break;
    default:
        // turn on previous case:
        enableCase = true;
        break;
}

话虽如此，我真的不建议这样做。根据您要解决的根本问题，几乎可以肯定有一种更明智的方法来实现这一点。也许使用 if/if else/else block 来测试其他地方设置的标志。