答案 0 :(得分:375)
答案 1 :(得分:316)
将以下内容粘贴到JavaScript的顶部(使用控制台之前):
/**
* 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
*
* Chrome 41.0.2272.118: debug,error,info,log,warn,dir,dirxml,table,trace,assert,count,markTimeline,profile,profileEnd,time,timeEnd,timeStamp,timeline,timelineEnd,group,groupCollapsed,groupEnd,clear
* Firefox 37.0.1: log,info,warn,error,exception,debug,table,trace,dir,group,groupCollapsed,groupEnd,time,timeEnd,profile,profileEnd,assert,count
* Internet Explorer 11: select,log,info,warn,error,debug,assert,time,timeEnd,timeStamp,group,groupCollapsed,groupEnd,trace,clear,dir,dirxml,count,countReset,cd
* Safari 6.2.4: debug,error,log,info,warn,clear,dir,dirxml,table,trace,assert,count,profile,profileEnd,time,timeEnd,timeStamp,group,groupCollapsed,groupEnd
* Opera 28.0.1750.48: debug,error,info,log,warn,dir,dirxml,table,trace,assert,count,markTimeline,profile,profileEnd,time,timeEnd,timeStamp,timeline,timelineEnd,group,groupCollapsed,groupEnd,clear
*/
(function() {
// Union of Chrome, Firefox, IE, Opera, and Safari console methods
var methods = ["assert", "cd", "clear", "count", "countReset",
"debug", "dir", "dirxml", "error", "exception", "group", "groupCollapsed",
"groupEnd", "info", "log", "markTimeline", "profile", "profileEnd",
"select", "table", "time", "timeEnd", "timeStamp", "timeline",
"timelineEnd", "trace", "warn"];
var length = methods.length;
var console = (window.console = window.console || {});
var method;
var noop = function() {};
while (length--) {
method = methods[length];
// define undefined methods as noops to prevent errors
if (!console[method])
console[method] = noop;
}
})();
函数闭包装置将变量的范围限定为不定义任何变量。这可以防范未定义的console
和未定义的console.debug
(以及其他缺少的方法)。
编辑:我注意到HTML5 Boilerplate在其js / plugins.js文件中使用了类似的代码,如果您正在寻找可能(可能)保持最新的解决方案-date。
答案 2 :(得分:73)
答案 3 :(得分:46)
要获得更强大的解决方案,请使用这段代码(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;
}
}
}());
答案 4 :(得分:13)
答案 5 :(得分:10)
如果您在IE8中打开console.log()
,则可以使用Developer Tools
,也可以在脚本标签上使用Console
文本框。
答案 6 :(得分:7)
if (typeof console == "undefined") {
this.console = {
log: function() {},
info: function() {},
error: function() {},
warn: function() {}
};
}
答案 7 :(得分:6)
在IE9中,如果未打开控制台,则此代码为:
alert(typeof console);
将显示“对象”,但此代码
alert(typeof console.log);
将抛出TypeError异常,但不返回未定义的值;
因此,保证版本的代码看起来与此类似:
try {
if (window.console && window.console.log) {
my_console_log = window.console.log;
}
} catch (e) {
my_console_log = function() {};
}
答案 8 :(得分:6)
我只在我的代码中使用console.log。所以我包括一个非常短的2线
var console = console || {};
console.log = console.log || function(){};
答案 9 :(得分:6)
基于之前的两个答案
和
的文件这是针对该问题的尽力而为的实现,这意味着如果存在实际存在的console.log,它将通过console.log填补不存在的方法的空白。
例如对于IE6 / 7,您可以使用alert替换日志记录(愚蠢但有效),然后包含下面的怪物(我称之为console.js): [随意删除你认为合适的评论,我留下参考,最小化者可以解决它们]:
<!--[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];
}
}
})();
答案 10 :(得分:2)
注意到OP正在使用带有IE的Firebug,所以假设它是Firebug Lite。这是一个时髦的情况,因为在打开调试器窗口时在IE中定义了控制台,但是当Firebug已经运行时会发生什么?不确定,但也许是&#34; firebugx.js&#34;方法可能是在这种情况下测试的好方法:
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)
答案 11 :(得分:1)
要在IE中进行调试,请查看此log4javascript
答案 12 :(得分:1)
console = console || {
debug: function(){},
log: function(){}
...
}
答案 13 :(得分:1)
对于仅限于console.log(无调试,跟踪,...)的IE8或控制台支持,您可以执行以下操作:
如果控制台或console.log未定义:为其创建虚拟函数 控制台功能(跟踪,调试,日志,......)
window.console = {
debug : function() {}, ...};
否则,如果定义了console.log(IE8)并且未定义console.debug(任何其他):将所有日志记录功能重定向到console.log,这样可以保留这些日志!
window.console = {
debug : window.console.log, ...};
不确定各种IE版本中的断言支持,但欢迎任何建议。也在这里发布了这个答案:How can I use console logging in Internet Explorer?
答案 14 :(得分:1)
我正在使用fauxconsole;我对css进行了一些修改,使其看起来更好但效果非常好。
答案 15 :(得分:0)
您可以使用以下内容提供额外的保险,您已涵盖所有基础。首先使用typeof
可以避免任何undefined
错误。使用===
还将确保该类型的名称实际上是字符串“undefined”。最后,您需要在函数签名中添加一个参数(我任意选择logMsg
)以确保一致性,因为您确实将打印到控制台的任何内容传递给日志功能。这也使您的智能感知准确,并避免JS知识IDE中的任何警告/错误。
if(!window.console || typeof console === "undefined") {
var console = { log: function (logMsg) { } };
}
答案 16 :(得分:0)
有时控制台可以在IE8 / 9中运行,但在其他时候会失败。这种不稳定的行为取决于您是否打开了开发人员工具,并在stackoverflow问题Does IE9 support console.log, and is it a real function?
中进行了描述答案 17 :(得分:0)
在IE9的子窗口中运行console.log遇到类似的问题,由window.open函数创建。
在这种情况下,似乎控制台仅在父窗口中定义,并且在子窗口中未定义,直到您刷新它们。同样适用于儿童窗户的儿童。
我通过将log登录到下一个函数(下面是模块的片段)来处理这个问题
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);
}
答案 18 :(得分:0)
TypeScript中控制台的存根:
class test (type)
def __str__(self)
return str.__class__
class vtest (object)
self.repr(str)
答案 19 :(得分:-2)
在遇到这么多问题之后(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!)我决定制作一个过度杀伤代码,永远不必再烦恼了:
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() {};
Personaly我只使用console.log和console.error,但是这段代码处理Mozzila开发者网络中显示的所有其他功能:https://developer.mozilla.org/en-US/docs/Web/API/console。 只需将代码放在页面顶部,就可以永久完成。
答案 20 :(得分:-10)
您可以直接在Firefox中使用console.log(...),但不能在IE中使用。在IE中,您必须使用window.console。