[removed] How do I print a message to the error console?

Question

How can I print a message to the error console, preferably including a variable?

For example, something like:

print(\'x=%d\', x);

Answer 1

As always, Internet Explorer is the big elephant in rollerskates that stops you just simply using console.log().

jQuery's log can be adapted quite easily, but is a pain having to add it everywhere. One solution if you're using jQuery is to put it into your jQuery file at the end, minified first:

function log()
{
    if (arguments.length > 0)
    {
        // Join for graceful degregation
        var args = (arguments.length > 1) ? Array.prototype.join.call(arguments, " ") : arguments[0];

        // This is the standard; Firebug and newer WebKit browsers support this.
        try {
            console.log(args);
            return true;
        } catch(e) {
            // Newer Opera browsers support posting erros to their consoles.
            try {
                opera.postError(args);
                return true;
            } 
            catch(e) 
            {
            }
        }

        // Catch all; a good old alert box.
        alert(args);
        return false;
    }
}