当遇到无效行时，javascript执行是否会停止？ [英] Does javascript execution stop when an invalid line is encountered?

问题描述

如果浏览器在网页上执行JavaScript并且遇到无效的JavaScript
（例如somerandomthingy;）此时JavaScript的执行是否停止，或者异步操作是否继续。此外，JavaScript事件仍然有效（例如onclick）。

If the browser is executing JavaScript on a web page and it encounters invalid JavaScript (e.g. somerandomthingy;) Does execution of JavaScript stop at that point, or do async operations continue. Also do JavaScript events still work (e.g. onclick).

推荐答案

是的，除了异步事件。 http://jsfiddle.net/pimvdb/R4dfJ/3/

Yes, except asynchronous ones. http://jsfiddle.net/pimvdb/R4dfJ/3/

DIY：

var a = 1, b, c;

setTimeout(function() {
    b = 2;
    console.log('Running', a, b, c);
}, 1000);

somerandomthingy;

c = 3;

未捕获的ReferenceError：somerandomthingy未定义

Uncaught ReferenceError: somerandomthingy is not defined

运行1 2未定义

所以：

• a 且 b 已设定


• c 尚未设置


• 超时仍然发生

• a and b have been set
• c has not been set
• Timeout still occurs

至于'on onclick仍然有用' - 好吧，如果处理程序是在运行的代码中设置的（即在错误之前），那么;如果它是在错误代码之后放置的，它将不会绑定处理程序，因此事件将不起作用。

As for 'does onclick still work' - well, if the handler is set in code that runs (i.e. before an error) it does; in case it is put after error code it won't bind the handler so events won't work.

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