我使用Firebug,并有一些语句像:

console.log("...");

在我的页面上。在IE8(可能是更早的版本),我得到脚本错误说“控制台”是未定义的。我试着把这个放在我页面的顶部:

<script type="text/javascript">
    if (!console) console = {log: function() {}};
</script>

我还是会得到错误。有办法消除错误吗?


当前回答

为了更健壮的解决方案,使用下面的代码(取自twitter的源代码):

// Avoid `console` errors in browsers that lack a console.
(function() {
    var method;
    var noop = function () {};
    var methods = [
        'assert', 'clear', 'count', 'debug', 'dir', 'dirxml', 'error',
        'exception', 'group', 'groupCollapsed', 'groupEnd', 'info', 'log',
        'markTimeline', 'profile', 'profileEnd', 'table', 'time', 'timeEnd',
        'timeStamp', 'trace', 'warn'
    ];
    var length = methods.length;
    var console = (window.console = window.console || {});

    while (length--) {
        method = methods[length];

        // Only stub undefined methods.
        if (!console[method]) {
            console[method] = noop;
        }
    }
}());

其他回答

在IE9的子窗口中运行console.log时遇到类似问题,由window创建。打开功能。

在这种情况下,控制台似乎只在父窗口中定义,在刷新子窗口之前没有定义。同样适用于子窗口的子窗口。

我处理这个问题通过包装log在下一个函数(下面是模块的片段)

getConsole: function()
    {
        if (typeof console !== 'undefined') return console;

        var searchDepthMax = 5,
            searchDepth = 0,
            context = window.opener;

        while (!!context && searchDepth < searchDepthMax)
        {
            if (typeof context.console !== 'undefined') return context.console;

            context = context.opener;
            searchDepth++;
        }

        return null;
    },
    log: function(message){
        var _console = this.getConsole();
        if (!!_console) _console.log(message);
    }

您可以在Firefox中直接使用console.log(…),但不能在ie中使用。在ie中,你必须使用window.console。

You can use the below to give an extra degree of insurance that you've got all bases covered. Using typeof first will avoid any undefined errors. Using === will also ensure that the name of the type is actually the string "undefined". Finally, you'll want to add a parameter to the function signature (I chose logMsg arbitrarily) to ensure consistency, since you do pass whatever you want printed to the console to the log function. This also keep you intellisense accurate and avoids any warnings/errors in your JS aware IDE.

if(!window.console || typeof console === "undefined") {
  var console = { log: function (logMsg) { } };
}

对于IE8或控制台支持仅限于console.log(没有调试,跟踪,…),您可以执行以下操作:

如果console或console.log未定义:为 控制台函数(跟踪,调试,日志,…) 窗口。控制台= { Debug: function(){},…}; 否则,如果console.log被定义(IE8)和console.debug(任何其他)没有定义:重定向所有日志功能到console.log,这允许保留这些日志! 窗口。控制台= { 调试:window.console.log,…};

不确定在各种IE版本中的assert支持,但欢迎任何建议。也在这里发布了这个答案:我如何在Internet Explorer中使用控制台登录?

注意到OP在IE中使用Firebug,所以假设它是Firebug Lite。当调试器窗口打开时,在IE中定义控制台,这是一种奇怪的情况,但是当Firebug已经在运行时会发生什么呢?不确定,但在这种情况下,"firebugx.js"方法可能是一个很好的测试方法:

来源:

https://code.google.com/p/fbug/source/browse/branches/firebug1.2/lite/firebugx.js?r=187

    if (!window.console || !console.firebug) {
        var names = [
            "log", "debug", "info", "warn", "error", "assert",
            "dir","dirxml","group","groupEnd","time","timeEnd",
            "count","trace","profile","profileEnd"
        ];
        window.console = {};
        for (var i = 0; i < names.length; ++i)
            window.console[names[i]] = function() {}
    }

(更新链接12/2014)