function Cat(){ this.name=‘小白‘; } Cat.prototype.color=‘white‘; Cat.prototype.skill=function(){ alert(‘吃鱼‘); } var cat1=new Cat(); console.log(cat1.name);//小白 console.log(Cat.prototype);//object console.log(cat1.prototype);//undefined console.log(cat1 instanceof Cat);//true console.log(cat1 instanceof Object);//true var obj=new Object(); Object.prototype.abc=‘123‘; var str=‘abcd‘; var arr=[‘1‘,‘2‘,‘3‘]; console.log(str.abc);//123 console.log(arr.abc);//123 String.prototype.len=function(){ return this.length; } alert(str.len()); console.log(str.__proto__);//String console.log(str.constructor);// String
console.log(str.constructor.prototype.constructor);// String
console.log(str.__proto__.__proto__);//Object Date.prototype.getWeek=function(){ var arr=[‘周末‘,‘周一‘,‘周二‘,‘周三‘,‘周四‘,‘周五‘,‘周六‘]; var index=this.getDay();//0-6 return arr[index]; } var date=new Date(); console.log(date.getWeek());//周六
Array.prototype.quchong=function (){ var arr=[]; this.sort(function (a,b){return a-b;}); for (var i = 0; i < this.length; i++) { if (this[i]==this[i+1]) { continue; }; arr.push(this[i]); }; return arr; } var arr1=[12,45,7,12,75,45,5,32,12]; console.log(arr1.quchong());
function fn1(){ var x=5; x++; alert(x); } fn1();//6 fn1();//6 fn1();//6 fn1();//6 function fn2(){ var x=5; function fn3(){ x++; alert(x); } return fn3; } var fn=fn2(); fn();//6 fn();//7 fn();//8 fn();//9
时间: 2024-10-08 07:06:08