Js 实现 C# Format方法

String.prototype.format = function (args) {
            if (arguments.length > 0) {
                var result = this;
                if (arguments.length == 1 && typeof (args) == "object") {
                    for (var key in args) {
                        var reg = new RegExp("({" + key + "})", "g");
                        result = result.replace(reg, args[key]);
                    }
                }
                else {
                    for (var i = 0; i < arguments.length; i++) {
                        if (arguments[i] == undefined) {
                            return "";
                        }
                        else {
                            var reg = new RegExp("({[" + i + "]})", "g");
                            result = result.replace(reg, arguments[i]);
                        }
                    }
                }
                return result;
            }
            else {
                return this;
            }
        }

//两种调用方式 
var template1="我是{0}，今年{1}了"; 
var template2="我是{name}，今年{age}了"; 
var result1=template1.format("loogn",22); 
var result2=template1.format({name:"loogn",age:22}); 
//两个结果都是"我是loogn，今年22了"