CODEWITHSUNDEEP
javascriptdebugging
helle
helle

Reputation: 11650

finding out if console is available

I was wondering, how can i find out with javascript if the console object is available?

i have the problem that if i forget to remove a debug output like console.log('sthg') i get errors in several browsers, if there is no firebug, or similar, active.

thanks for help

next to that problem i am interested in all informations about the console object. has anybody some documentation link, or so? is it a standard? and so on...

Upvotes: 47

Views: 37469

Answers (8)

Nadeem Yasin
Nadeem Yasin

Reputation: 4524

try{
console.log("test")
}
catch(e){
console={},
console.log=function(a){}
}

just put it at the top of your JS file and then use console.log(); without any worry for browser error, i also had this error in IE9

Upvotes: 5

Andy E
Andy E

Reputation: 344517

Check the property exists as a member of window:

if (window.console) {
}

next to that problem i am interested in all informations about the console object. has anybody some documentation link, or so? is it a standard? and so on...

Check out the Firebug documentation for the Console API; Chrome and Safari implement most, but not all, of the methods listed there. There's no standard defining what should be in the console, so you'll need to test each browser to see if it supports the feature.

Upvotes: 66

Asish Sinha
Asish Sinha

Reputation: 61

Simplest way would be:

if (window.console){
   console.log('do something');
}

instead of just writing:

console.log('do something');

Upvotes: 2

code_monk
code_monk

Reputation: 10120

here's what i use. bear in mind that i am only half-heartedly supporting browsers with no support for console. and i only ever use console.log(), but you can see how it can be extended to support console.dir(), console.info(), etc

var console = console || {
    "log": function(stuff) {}
};

I like it because calling it does not cause an error, but it returns [undefined], which i think is appropriate.

Note that many many people before (and after) us have written similar polyfills:

https://gist.github.com/search?q=console+%7C%7C+console

Upvotes: 8

Bas van Ommen
Bas van Ommen

Reputation: 1293

I always include this in the top of my HTML-header before I load anything else. Debugging with console.debug is just too long for me. And I like to toggle the usage of these console functions.

Don't know how optimized the code is, but it always does the job.

(function() {
    var consoleDisabled = false;
    if (consoleDisabled) {
        window.console = undefined;
    }
    if (window.console == undefined) {
        window.console = {
            debug: function() {
                return true;
            },
            info: function() {
                return false;
            },
            warn: function() {
                return false;
            },
            log: function() {
                return false;
            }
        }
    }
    debug = (function(args) {
        window.console.debug(args);
    });
    info = (function(args) {
        window.console.info(args);
    });
    warn = (function(args) {
        window.console.warn(args);
    });
    log = (function(args) {
        window.console.log(args);
    });
})();
debug(somevar);
info(somevar);
warn(somevar);
log(somevar);

Upvotes: 3

Matthew O'Riordan
Matthew O'Riordan

Reputation: 8211

A nice simple and short way of outputting to the console safely is as follows:

window.console && console.log('Debug message');

Upvotes: 32

Robby Pond
Robby Pond

Reputation: 73484

Defined by firebug, IE8 (need to open the developer tools with F12), Chrome, etc but there is no defined spec for it. There is a console.log wrapper that makes it a very easy to use, cross browser logging solution so if the console doesn't exist your code doesn't explode.

Upvotes: 6

Syl
Syl

Reputation: 2783

maybe...

if (console) {
    // do stuff
}

Upvotes: -4

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