实例1、js的基础语法
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>js基础语法</title>
<script type="text/javascript" >
//字面量输出
// document.write('hahahahaha');
// console.log('犇犇');
function add(){
let m= arguments.length; //返回参数的数量
switch(m){
case 0:
return '至少一个参数';
break;
case 1:
return arguments[0];
break;
case 2:
return arguments[0]+arguments[1];
break;
case 3:
return arguments[0]+arguments[1]+arguments[2];
break;
default:
return '参数过多';
break;
}
}
console.log(add(10,20,30,40));
</script>
</head>
<body>
</body>
</html>运行实例 »
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实例 js创建对象1
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>对象</title>
<script >
let obj = new Object();//创建函数
obj.name='chang';
obj.age=1;
obj.getName=function(){return this.name};
obj.getAge=function(){return this.age};
console.log(obj.getName());
console.log(obj.getAge());
let obj1 = {
name:'benben',
'sex':'baby',
getName:function (){return this.name},
getSex:function (){return this.sex}
}
// obj1.name;
console.log(obj1.name);
console.log(obj1.getName());
console.log(obj1['sex']);
console.log(obj1.getSex());
console.log(obj1);
</script>
</head>
<body>
</body>
</html>运行实例 »
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实例 js创建对象2
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>创建对象</title>
<script type="text/javascript">
//1、创建函数 （方法） 用来创建对象
function creatObj(name,age){
let obj = new Object();
obj.name= name;
obj.age=age;
return obj;
}
let obj1=creatObj('ben',1);
let obj2=creatObj('ben2',1);
let obj3=creatObj('ben3',1);
console.log(obj1);
console.log(obj2);
console.log(obj3);
//2、创建构造函数 (方法) 由工厂函数演变而来
function Stu(name,age){
// let obj = new Object();
this.name = name;
this.age = age;
this.getName = function(){
return this.name;
}
// return obj;
}
//new Stu('benben',2);
//相当于
let obj4 = new Stu('benben',2);
console.log(obj4);
// 3、原型：所有实例可共享的属性或方法
function Stu(){
}
//实现方法的共享
Stu.prototype.getName=function(){
return this.name;
}
Stu.prototype.name='benbenben';
Stu.prototype.age=3;
let obj5 = new Stu();
console.log(obj5);
</script>
</head>
<body>
</body>
</html>运行实例 »
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