Is there a JavaScript function that can pad a string to get to a determined length?

Question

I am in need of a JavaScript function which can take a value and pad it to a given length (I need spaces, but anything would do). I found this:

Code:

Answer 1

Here's a simple function that I use.

var pad=function(num,field){
    var n = '' + num;
    var w = n.length;
    var l = field.length;
    var pad = w < l ? l-w : 0;
    return field.substr(0,pad) + n;
};

For example:

pad    (20,'     ');    //   20
pad   (321,'     ');    //  321
pad (12345,'     ');    //12345
pad (   15,'00000');    //00015
pad (  999,'*****');    //**999
pad ('cat','_____');    //__cat