I would like to save the output of the console.log() function as an object, or as a variable. I'm mainly interested in receiving object-results, as well as the line numbers.

The following is just to demonstrate, what i'm looking for:

var myobj = {"key":"value"}; // (<< in 'myjs.js, line 123)
var mylog = console.log( myobj );

// output mylog: {"key":"value"}, myjs.js:123

Thanks in advance for any help!

I would like to save the output of the console.log() function as an object, or as a variable. I'm mainly interested in receiving object-results, as well as the line numbers.

The following is just to demonstrate, what i'm looking for:

var myobj = {"key":"value"}; // (<< in 'myjs.js, line 123)
var mylog = console.log( myobj );

// output mylog: {"key":"value"}, myjs.js:123

Thanks in advance for any help!

• javascript
• jquery
• debugging
• console

• console.log() does not return any value... so it is not possible with console.log – Arun P Johny Commented Aug 19, 2013 at 7:27
• infact myObj is myLog, Just assign it – Moazzam Khan Commented Aug 19, 2013 at 7:27
• Technically, you could overwrite the function in the console's prototype, but that seems like a terrible idea. – Fenixp Commented Aug 19, 2013 at 7:28
• Do you want to save output as a String or an Object? – Moazzam Khan Commented Aug 19, 2013 at 7:33
• I would prefer as an object, but since i'm mainly interested in the line number, as a string would be a big help as well. – Elvis Commented Aug 19, 2013 at 7:39

4 Answers 4

you can use new Error().lineNumber to get line number For more info about determining line number - determining line number

You can overwrite console.log and call Error().stack in google chrome it show line numbers.

In google chrome stack look like this:

Error
    at Error (<anonymous>)
    at Console.console.log (http://localhost/test.js:6:27)
    at foo (http://localhost/test.js:13:13)
    at http://localhost/test.js:16:1 

So the code need to fetch 3 line and remove "at http://localhost" and number of chars

(function(log) {
    console.log = function(o) {
        var stack = Error().stack.split('\n');
        log.call(console, JSON.stringify(o) + ', ' + stack[3].
            replace(/.*http:\/\/[^\/]*|:[0-9]+\)$/g, ''));
    };
})(console.log);


function foo() {
    console.log({foo: 'bar'});
}

foo();

Try saving myObj object. That is what the logger will log.

you can try this from the link Read the output of console.log

function myFunctionThatMightHaveAnError(){
    // instead of just failing silently, actually throw an error
    $.error("My special error");
}
// Then use a try/catch block to handle it
try {
    myFunctionThatMightHaveAnError();
    alert("No error!"); // this line would only run if no error were thrown
} catch (e) {
    if(e == "My special error") {
        // Handle error
    }
}