Simple string formatter with integer and float operators.

String.format.js

String.prototype.format = function() {
    var string = this.toString();
    if (arguments.length) {
        var tokens = string.match(/%([sdf])/g) || [],
            token, i = 0, replace;
        while (token = tokens.shift()) {
            replace = arguments[i++];
            switch (token) {
                case "%d":
                    string = string.replace(token, parseInt(replace, 10) || 0);
                    break;
                case "%f":
                    string = string.replace(token, parseFloat(replace) || 0);
                    break;
                default:
                    string = string.replace(token, replace);
            }
        }
    }
    return string;
};