Js语言精粹经典用法

1. 扩充类型的功能

Function.prototype.method = function(name, func){
     if(!this.prototype[name]){
     this.prototype[name] = func;
     }
     return this;
}

String.method('deentityfy',function(){  
   var entity={
     quot:'"',
     lt:'<',
     gt:'>'
   };
  
  return function(){ 
   
    return this.replace(/&([^&;]+);/g,
                        function(a,b){
      var r = entity[b];
      return typeof r==='string' ? r:a;
    });
  };
}());
console.log('<>'.deentityfy());  // <>