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