JAVASCRIPT中经典面试题

 1 //1、try catch finally中的return 2   var n=1; 3   function fun(){ 4     try{ 5       n++; 6       m++;//报错 7       return n; 8     }catch(err){ 9       n++;10       return n;11     }finally{12       n++;13       //return n;14     }15   }16   console.log(fun());//317   console.log(n);//4

/*作用域和作用域链*/	var n=10;	function fun(n){		n--;		console.log(n);	}	console.log(fun(n)); //9	console.log(n); //10

 1 /*new Function*/ 2   var i=5; 3   function fun(){ 4     var i=4; 5     //var f1=new Function("console.log(i)"); 6     var f1=function(){console.log(i);}; 7     console.log(f1); 8     f1(); 9   }10   fun();//4

 1 /*callback 与 this*/ 2   var o={ 3     n:1, 4     fun:function(){ 5       var self=this;//留住this 6       console.log(self.n++); 7       setTimeout(function(){ 8         self.fun(); 9       },1000);10     }11   }12   o.fun();//this-->o

1 /*DOM中的闭包问题*/2   function fun(){3     var li=document.getXX...;4     btn.onclick=function(){5       li.xx=xx;6     }//li将永远无法释放，即使刷新页面也不行7   }

1 /*引用类型的共有属性*/2   function Student(){}3   Student.prototype.arr=[];4   var lilei=new Student();5   var hmm=new Student();6   lilei.arr.push(1);//this[this.length]=17   hmm.arr[1]=2;8   console.log(lilei.arr);//[1,2]9   console.log(hmm.arr);//[1,2]

1 /*继承父类型共有方法*/2   function Student(){}3   Student.prototype=[];4   var lilei=new Student();5   lilei.push(1);//this[this.length]=value;6   var hmm=new Student();7   hmm.push(2);8   console.log(lilei);9   console.log(hmm);

 1 /*私有属性，公有属性*/ 2   function Student(){ 3     var prop="私有属性";//私有属性 4     this.prop="公有属性"; //公有属性 5     var fun=function(){//私有方法 6       console.log("调用私有方法"); 7       console.log(prop); 8     } 9     this.fun=function(){//公有方法10       console.log("调用公有方法");11       fun();//this-->window12       console.log(prop);13       console.log(this.prop);14     }15   }16   var lilei=new Student();17   lilei.fun();//公有

1 //阻碍事件2 for(var i=0;i<3;i++){3     setTimeout(function(){4       console.log(i);5     },10)6   }7   alert("hello");

 1 function MyObj(){ 2     this.p.pid++; 3   } 4   MyObj.prototype.p={"pid":0}; 5   MyObj.prototype.getNum=function(num){ 6     return this.p.pid+num; 7   } 8   var obj1=new MyObj();  9   var obj2=new MyObj(); //p.pid=210   console.log(obj1.getNum(1)+obj2.getNum(2));//7

 1 /**/ 2   function fun(n,o){ 3     console.log(o); 4     return {fun:function(m){ 5         return fun(m,n); 6       } 7     } 8   } 9   var a=fun(0);//undefined10   //a-->{fun:function(m){return fun(m,n)}}11   a.fun(1); a.fun(2); a.fun(3); //0 0 012   var b=fun(0).fun(1).fun(2).fun(3); //0 1 213   var c=fun(0).fun(1); c.fun(2);c.fun(3); //0 1 1

原标题：JAVASCRIPT中经典面试题

关键词：JavaScript