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
我使用ibroker和容易地设法停止脚本
stopScript();
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 '';
}
"exit"函数通常退出程序或脚本,并以错误消息作为参数。例如php中的die(…)
die("sorry my fault, didn't mean to but now I am in byte nirvana")
在JS中等效的是用throw关键字发出错误信号,如下所示:
throw new Error();
你可以很容易地测试这个:
var m = 100;
throw '';
var x = 100;
x
>>>undefined
m
>>>100
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。
退出JS或Node脚本的方法有很多。以下是最相关的:
// This will never exit!
setInterval((function() {
return;
}), 5000);
// This will exit after 5 seconds, with signal 1
setTimeout((function() {
return process.exit(1);
}), 5000);
// This will also exit after 5 seconds, and print its (killed) PID
setTimeout((function() {
return process.kill(process.pid);
}), 5000);
// This will also exit after 5 seconds and create a core dump.
setTimeout((function() {
return process.abort();
}), 5000);
如果你在REPL中(即在命令行上运行node之后),你可以输入.exit退出。
这段代码将停止当前窗口中所有javascript的执行:
(,);
例子
console.log('READY!'); setTimeout(()=>{ /* animation call */ div.className = "anim"; console.log('SET!'); setTimeout(()=>{ setTimeout(()=>{ console.log('this code will never be executed'); },1000); console.log('GO!'); /* BOMB */ for(;;); console.log('this code will never be executed'); },1000); },1000); #div { position: fixed; height: 1rem; width: 1rem; left: 0rem; top: 0rem; transition: all 5s; background: red; } /* this <div> will never reached the right bottom corner */ #div.anim { left: calc(100vw - 1rem); top: calc(100vh - 1rem); } <div id="div"></div>
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