中英文時，佔位符轉換實體對象
String.prototype.format= function() {
if(arguments.length === 0) return this;
var param = arguments[0], str= this;
if(typeof(param) === 'object') {
for(var key in param)
str = str.replace(new RegExp("\\{" + key + "\\}", "g"), param[key]);
return str;
} else {
for(var i = 0; i < arguments.length; i++)
str = str.replace(new RegExp("\\{" + i + "\\}", "g"), arguments[i]);
return str;
}
};
var _obj = {a:'1',b:'2'};
var m = "test{a} to {b}".format(_obj);