Search code examples
javascripterror-handlingundefined

Is there a way to handle undefined functions being called in JavaScript?


If I have a function like the following:

function catchUndefinedFunctionCall( name, arguments )
{
    alert( name + ' is not defined' );
}

and I do something silly like

foo( 'bar' );

when foo isn't defined, is there some way I can have my catch function called, with name being 'foo' and arguments being an array containing 'bar'?


Solution

  • There is in Mozilla Javascript 1.5 anyway (it's nonstandard).

    Check this out:

    var myObj = {
        foo: function () {
            alert('foo!');
        }
        , __noSuchMethod__: function (id, args) {
            alert('Oh no! '+id+' is not here to take care of your parameter/s ('+args+')');
        } 
    }
    myObj.foo();
    myObj.bar('baz', 'bork'); // => Oh no! bar is not here to take care of your parameter/s (baz,bork)
    

    Pretty cool. Read more at https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/Object/NoSuchMethod