我如何退出JavaScript脚本,就像PHP的退出或死亡?我知道这不是最好的编程实践,但我需要这样做。


当前回答

简单地创建一个BOOL条件, 这里不需要复杂的代码。

即使你把它变成true/或多次, 它会给你一条解,而不是多条解 基本上就是这么简单。

其他回答

JavaScript相当于PHP的die。顺便说一句,它只是调用exit()(谢谢splattne):

function exit( status ) {
    // http://kevin.vanzonneveld.net
    // +   original by: Brett Zamir (http://brettz9.blogspot.com)
    // +      input by: Paul
    // +   bugfixed by: Hyam Singer (http://www.impact-computing.com/)
    // +   improved by: Philip Peterson
    // +   bugfixed by: Brett Zamir (http://brettz9.blogspot.com)
    // %        note 1: Should be considered expirimental. Please comment on this function.
    // *     example 1: exit();
    // *     returns 1: null

    var i;

    if (typeof status === 'string') {
        alert(status);
    }

    window.addEventListener('error', function (e) {e.preventDefault();e.stopPropagation();}, false);

    var handlers = [
        'copy', 'cut', 'paste',
        'beforeunload', 'blur', 'change', 'click', 'contextmenu', 'dblclick', 'focus', 'keydown', 'keypress', 'keyup', 'mousedown', 'mousemove', 'mouseout', 'mouseover', 'mouseup', 'resize', 'scroll',
        'DOMNodeInserted', 'DOMNodeRemoved', 'DOMNodeRemovedFromDocument', 'DOMNodeInsertedIntoDocument', 'DOMAttrModified', 'DOMCharacterDataModified', 'DOMElementNameChanged', 'DOMAttributeNameChanged', 'DOMActivate', 'DOMFocusIn', 'DOMFocusOut', 'online', 'offline', 'textInput',
        'abort', 'close', 'dragdrop', 'load', 'paint', 'reset', 'select', 'submit', 'unload'
    ];

    function stopPropagation (e) {
        e.stopPropagation();
        // e.preventDefault(); // Stop for the form controls, etc., too?
    }
    for (i=0; i < handlers.length; i++) {
        window.addEventListener(handlers[i], function (e) {stopPropagation(e);}, true);
    }

    if (window.stop) {
        window.stop();
    }

    throw '';
}

这是一个例子, 如果条件存在,则终止脚本。 我使用这个在我的SSE客户端javascript,如果

<script src="sse-clint.js" host="https://sse.host" query='["q1,"q2"]' ></script>

不能直接从JSON解析…

if( ! SSE_HOST  ) throw new Error(['[!] SSE.js: ERR_NOHOST - finished !']);

... 总之,总的思想是:

if( error==true) throw new Error([ 'You have This error' ,  'At this file', 'At this line'  ]);

这将终止/死亡你的javascript脚本

简单地创建一个BOOL条件, 这里不需要复杂的代码。

即使你把它变成true/或多次, 它会给你一条解,而不是多条解 基本上就是这么简单。

如果你只是想停止执行更多的代码而不“抛出”任何错误,你可以暂时覆盖window。如cross-exit所示:

function exit(code) {
    const prevOnError = window.onerror
    window.onerror = () => {
        window.onerror = prevOnError
        return true
    }

    throw new Error(`Script termination with code ${code || 0}.`)
}

console.log("This message is logged.");
exit();
console.log("This message isn't logged.");

If you're looking for a way to forcibly terminate execution of all Javascript on a page, I'm not sure there is an officially sanctioned way to do that - it seems like the kind of thing that might be a security risk (although to be honest, I can't think of how it would be off the top of my head). Normally in Javascript when you want your code to stop running, you just return from whatever function is executing. (The return statement is optional if it's the last thing in the function and the function shouldn't return a value) If there's some reason returning isn't good enough for you, you should probably edit more detail into the question as to why you think you need it and perhaps someone can offer an alternate solution.

注意,在实践中,大多数浏览器的Javascript解释器在遇到错误时会简单地停止运行当前脚本。所以你可以做一些事情,比如访问一个未设置变量的属性:

function exit() {
    p.blah();
}

它可能会中止脚本。但你不应该指望它,因为它根本不是标准的,而且它看起来真的是一个糟糕的做法。

编辑:好吧,也许这不是一个很好的答案Ólafur的光。尽管他链接到的die()函数基本上实现了我的第二段,即它只是抛出一个错误。