How to get JavaScript caller function line number and caller source URL

Question

This works for me in chrome/QtWebView

function getErrorObject(){
    try { throw Error('') } catch(err) { return err; }
}

var err = getErrorObject();
var caller_line = err.stack.split("\n")[4];
var index = caller_line.indexOf("at ");
var clean = caller_line.slice(index+2, caller_line.length);

kangax's solution introduces unnecessary try..catch scope. If you need to access the line number of something in JavaScript (as long as you are using Firefox or Opera), just access (new Error).lineNumber.

I was surprised that most of these answers assumed that you wanted to handle an error rather than just output helpful debug traces for normal cases as well.

For example, I like using a console.log wrapper like this:

consoleLog = function(msg) {//See https://stackoverflow.com/a/27074218/470749
    var e = new Error();
    if (!e.stack) {
        try {
            // IE requires the Error to actually be thrown or else the 
            // Error's 'stack' property is undefined.
            throw e;
        } catch (e) {
            if (!e.stack) {
                //return 0; // IE < 10, likely
            }
        }
    }
    var stack = e.stack.toString().split(/\r\n|\n/);
    if (msg === '') {
        msg = '""';
    }
    console.log(msg, '          [' + stack[1] + ']');        
}

This ends up printing an output such as the following to my console:

1462567104174 [getAllPosts@http://me.com/helper.js:362:9]

See https://stackoverflow.com/a/27074218/ and also A proper wrapper for console.log with correct line number?

I realize this is an old question but there is now a method called console.trace("Message") that will show you the line number and the chain of method calls that led to the log along with the message you pass it. More info on javascript logging tricks are available here at freecodecamp and this medium blog post

This is often achieved by throwing an error from the current context; then analyzing error object for properties like lineNumber and fileName (which some browsers have)

function getErrorObject(){
  try { throw Error('') } catch(err) { return err; }
}

var err = getErrorObject();

err.fileName;
err.lineNumber; // or `err.line` in WebKit

Don't forget that callee.caller property is deprecated (and was never really in ECMA 3rd ed. in the first place).

Also remember that function decompilation is specified to be implementation dependent and so might yield quite unexpected results. I wrote about it here and here.