根据之前的两个答案

维尼修斯·莫赖斯 曾国藩

和文件

Internet Explorer (ie10) Safari(2012。07. 23)。 Firefox(2013。05. 20)。 Chrome(2013。01. 25.)和Chrome(2012。10. 04)。 还有我的一些知识

下面是针对该问题的最佳实现，这意味着如果有一个真正存在的console.log，它将通过console.log填补不存在方法的空白。

例如，对于IE6/7，你可以用alert代替日志记录(愚蠢但有效)，然后包括下面的怪物(我称之为console.js): [请随意删除你认为合适的评论，我把它们留作参考，最小化可以解决它们]:

<!--[if lte IE 7]>
<SCRIPT LANGUAGE="javascript">
    (window.console = window.console || {}).log = function() { return window.alert.apply(window, arguments); };
</SCRIPT>
<![endif]-->
<script type="text/javascript" src="console.js"></script>

和console.js:

    /**
     * Protect window.console method calls, e.g. console is not defined on IE
     * unless dev tools are open, and IE doesn't define console.debug
     */
    (function() {
        var console = (window.console = window.console || {});
        var noop = function () {};
        var log = console.log || noop;
        var start = function(name) { return function(param) { log("Start " + name + ": " + param); } };
        var end = function(name) { return function(param) { log("End " + name + ": " + param); } };

        var methods = {
            // Internet Explorer (IE 10): http://msdn.microsoft.com/en-us/library/ie/hh772169(v=vs.85).aspx#methods
            // assert(test, message, optionalParams), clear(), count(countTitle), debug(message, optionalParams), dir(value, optionalParams), dirxml(value), error(message, optionalParams), group(groupTitle), groupCollapsed(groupTitle), groupEnd([groupTitle]), info(message, optionalParams), log(message, optionalParams), msIsIndependentlyComposed(oElementNode), profile(reportName), profileEnd(), time(timerName), timeEnd(timerName), trace(), warn(message, optionalParams)
            // "assert", "clear", "count", "debug", "dir", "dirxml", "error", "group", "groupCollapsed", "groupEnd", "info", "log", "msIsIndependentlyComposed", "profile", "profileEnd", "time", "timeEnd", "trace", "warn"

            // Safari (2012. 07. 23.): https://developer.apple.com/library/safari/#documentation/AppleApplications/Conceptual/Safari_Developer_Guide/DebuggingYourWebsite/DebuggingYourWebsite.html#//apple_ref/doc/uid/TP40007874-CH8-SW20
            // assert(expression, message-object), count([title]), debug([message-object]), dir(object), dirxml(node), error(message-object), group(message-object), groupEnd(), info(message-object), log(message-object), profile([title]), profileEnd([title]), time(name), markTimeline("string"), trace(), warn(message-object)
            // "assert", "count", "debug", "dir", "dirxml", "error", "group", "groupEnd", "info", "log", "profile", "profileEnd", "time", "markTimeline", "trace", "warn"

            // Firefox (2013. 05. 20.): https://developer.mozilla.org/en-US/docs/Web/API/console
            // debug(obj1 [, obj2, ..., objN]), debug(msg [, subst1, ..., substN]), dir(object), error(obj1 [, obj2, ..., objN]), error(msg [, subst1, ..., substN]), group(), groupCollapsed(), groupEnd(), info(obj1 [, obj2, ..., objN]), info(msg [, subst1, ..., substN]), log(obj1 [, obj2, ..., objN]), log(msg [, subst1, ..., substN]), time(timerName), timeEnd(timerName), trace(), warn(obj1 [, obj2, ..., objN]), warn(msg [, subst1, ..., substN])
            // "debug", "dir", "error", "group", "groupCollapsed", "groupEnd", "info", "log", "time", "timeEnd", "trace", "warn"

            // Chrome (2013. 01. 25.): https://developers.google.com/chrome-developer-tools/docs/console-api
            // assert(expression, object), clear(), count(label), debug(object [, object, ...]), dir(object), dirxml(object), error(object [, object, ...]), group(object[, object, ...]), groupCollapsed(object[, object, ...]), groupEnd(), info(object [, object, ...]), log(object [, object, ...]), profile([label]), profileEnd(), time(label), timeEnd(label), timeStamp([label]), trace(), warn(object [, object, ...])
            // "assert", "clear", "count", "debug", "dir", "dirxml", "error", "group", "groupCollapsed", "groupEnd", "info", "log", "profile", "profileEnd", "time", "timeEnd", "timeStamp", "trace", "warn"
            // Chrome (2012. 10. 04.): https://developers.google.com/web-toolkit/speedtracer/logging-api
            // markTimeline(String)
            // "markTimeline"

            assert: noop, clear: noop, trace: noop, count: noop, timeStamp: noop, msIsIndependentlyComposed: noop,
            debug: log, info: log, log: log, warn: log, error: log,
            dir: log, dirxml: log, markTimeline: log,
            group: start('group'), groupCollapsed: start('groupCollapsed'), groupEnd: end('group'),
            profile: start('profile'), profileEnd: end('profile'),
            time: start('time'), timeEnd: end('time')
        };

        for (var method in methods) {
            if ( methods.hasOwnProperty(method) && !(method in console) ) { // define undefined methods as best-effort methods
                console[method] = methods[method];
            }
        }
    })();

我使用的是fauxconsole;我修改了css一点，使它看起来更好，但工作得很好。

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) { } };
}

在有这么多问题之后(很难调试错误，因为如果你打开开发人员控制台，错误就不再发生了!)我决定做一个多余的代码，这样就再也不用为这个问题烦恼了:

if (typeof window.console === "undefined")
    window.console = {};

if (typeof window.console.debug === "undefined")
    window.console.debug= function() {};

if (typeof window.console.log === "undefined")
    window.console.log= function() {};

if (typeof window.console.error === "undefined")
    window.console.error= function() {alert("error");};

if (typeof window.console.time === "undefined")
    window.console.time= function() {};

if (typeof window.console.trace === "undefined")
    window.console.trace= function() {};

if (typeof window.console.info === "undefined")
    window.console.info= function() {};

if (typeof window.console.timeEnd === "undefined")
    window.console.timeEnd= function() {};

if (typeof window.console.group === "undefined")
    window.console.group= function() {};

if (typeof window.console.groupEnd === "undefined")
    window.console.groupEnd= function() {};

if (typeof window.console.groupCollapsed === "undefined")
    window.console.groupCollapsed= function() {};

if (typeof window.console.dir === "undefined")
    window.console.dir= function() {};

if (typeof window.console.warn === "undefined")
    window.console.warn= function() {};

我个人只使用console.log和console。错误，但这段代码处理所有其他函数显示在Mozzila开发者网络:https://developer.mozilla.org/en-US/docs/Web/API/console。 只要把代码放在页面的顶部，你就永远不用这样做了。

Try

if (!window.console) console = ...

未定义的变量不能直接引用。但是，所有全局变量都是全局上下文(浏览器为窗口)同名的属性，访问未定义的属性是可以的。

或者使用if (typeof console === 'undefined') console =…如果你想避开神奇的变量窗口，请参阅@Tim Down的回答。

有时控制台可以在IE8/9中工作，但在其他时候会失败。这种不稳定的行为取决于你是否打开了开发工具，并在stackoverflow问题中描述了IE9是否支持console.log，这是一个真实的函数吗?