Equivalent of String.format in jQuery

The source code for ASP.NET AJAX is available for your reference, so you can pick through it and include the parts you want to continue using into a separate JS file. Or, you can port them to jQuery.

Here is the format function...

String.format = function() {
  var s = arguments[0];
  for (var i = 0; i < arguments.length - 1; i++) {       
    var reg = new RegExp("\\{" + i + "\\}", "gm");             
    s = s.replace(reg, arguments[i + 1]);
  }

  return s;
}

And here are the endsWith and startsWith prototype functions...

String.prototype.endsWith = function (suffix) {
  return (this.substr(this.length - suffix.length) === suffix);
}

String.prototype.startsWith = function(prefix) {
  return (this.substr(0, prefix.length) === prefix);
}

This is a faster/simpler (and prototypical) variation of the function that Josh posted:

String.prototype.format = String.prototype.f = function() {
    var s = this,
        i = arguments.length;

    while (i--) {
        s = s.replace(new RegExp('\\{' + i + '\\}', 'gm'), arguments[i]);
    }
    return s;
};

Usage:

'Added {0} by {1} to your collection'.f(title, artist)
'Your balance is {0} USD'.f(77.7) 

I use this so much that I aliased it to just f, but you can also use the more verbose format. e.g. 'Hello {0}!'.format(name)