Question

I have this code:

function get_id_from_coords (x, y)
{
    x = parseInt(x);
    y = parseInt(y);

    if (x < 0)
    {
        x = (x + 6) * 60;
    }
    else
    {
        x = (x + 5) * 60;
    }
    if (y < 0)
    {
        y = (y + 6) * 60;
    }
    else
    {
        y = (y + 5) * 60;
    }

    $('#planets').children().each(function(){
        if ($(this).attr('x') == x) {
            if ($(this).attr('y') == y) {
                alert (parseInt($(this).attr('id')));
                return parseInt($(this).attr('id'));
            }
        }
    });
}
alert(get_id_from_coords(x, y));

However, from this code I get two popups:
First, from inside the function, I get the proper value (like 63), but then, when I alert the return value, I just get undefined.

Answer 1

You get undefined as you function doesn’t return – the last statement is a call to each function and it’s not a return statement. If you put a return, e.g.

...
return $('#planets').children().each(function(){
    if ($(this).attr('x') == x) {
        if ($(this).attr('y') == y) {
            alert (parseInt($(this).attr('id')));
            return parseInt($(this).attr('id'));
        }
    }
});

it will return something – in this case, based on the docs:

• http://api.jquery.com/jQuery.each/

  The method returns its first argument, the object that was iterated.
  

it will return the children of #planets.

If you want to find some value specifically using each, then you can do something like this:

...
val toRet;
$('#planets').children().each(function(){
    if ($(this).attr('x') == x) {
        if ($(this).attr('y') == y) {
            toRet = parseInt($(this).attr('id'));
        }
    }
});
return toRet;