在IE中测试console.log语句 [英] Testing for console.log statements in IE

问题描述

可能重复：

'控制台'是Internet Explorer的未定义错误

如果您的代码中包含 console.log 语句，Internet Explorer将抛出JavaScript错误（至少在我们的Intranet用户安装的IE7中）。

If you have console.log statements in your code, Internet Explorer will throw a JavaScript error (at least in IE7 which is what our intranet users have installed).

我在大多数开发测试中使用Firefox主要是因为Firebug提供的功能（我使用了很多控制台语句）但我还需要在IE中测试。

I am using Firefox for most of my development testing primarily because of the functionality provided by Firebug (where I use a lot of console statements) but I also need to test in IE.

如果我将以下内容添加到我的JavaScript中，则不会抛出错误。

if I add the following to my JavaScript, the error does not get thrown.

var debugging = false;
if (typeof console == "undefined") 
    var console = { log: function() {} };  

问题是如果调试模式为false，我想触发一个事件。如果我创建一个函数来测试调试是否为false并执行操作（此时只是一个警报），但是当我尝试执行以下操作时，我收到IE错误，指出控制台未定义。

The problem is that I would like to trigger an event if debugging mode is false. If I create a function to test whether debugging is false and do an action (at this point just an alert) but when I try do the following I receive an IE error saying Console is not defined.

var debugging = false; // or true   
if (typeof console == "undefined") 
    var console = { log: function() {consoleMsg()} };   

function consoleMsg() {
    if(!debugging) {
    alert('Console.log event in Production Code');
}   

如果有人可以帮我修改我的代码，请提供更好的帮助方式我实现了自己的目标，或者指导我一个资源来教育自己，我会非常感激。

If someone could help me to fix my code, provide a better way to help me achieve my goal, or direct me to a resource to edumacate myself I would be very appreciative.

推荐答案

你没有跳过所有这些箍。在使用它之前，只需检查控制台是否存在。

You don't have to jump through all these hoops. Simply check if the console exists before using it.

所以，而不是：

console.log('foo');

使用：

window.console && console.log('foo');

...并且您不会收到任何错误。

...and you won't get any errors.

或者，您可以在脚本顶部检查它，如果它未定义，只需用空函数填充它：

Alternatively, you could just check for it at the top of your script, and if it's undefined, just fill it with an empty function:

// At the top of your script:
if ( ! window.console ) console = { log: function(){} };
// If you use other console methods, add them to the object literal above

// Then, anywhere in your script:
console.log('This message will be logged, but will not cause an error in IE7');

---

对于更强大的解决方案，请使用代码（取自twitter的源代码）：

---

For a more robust solution, use this piece of code (taken from twitter's source code):

// 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;
        }
    }
}());

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