<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
</body>
</html>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
<script>
const person = {
name:'lyj',
age:19,
sex:1
}
//对象结构
const {name,age} = person
console.log(name,age);
//字符串扩展
let str ='linyijia';
console.log(str.startsWith('lin'));
console.log(str.endsWith('lin'));
console.log(str.includes('lin'));
//字符串模版
let ss=`我叫${name},今年${age}`
console.log(ss);
//默认值
function show(arg1='hello'){
console.log(arg1+ss);
}
//不定参数
function showmsg(...values){
console.log("参数数量"+values.length);
}
show();
showmsg(name,age,ss);
//箭头函数 省掉了function 等价于
// function sumvalue((v1,v2){
// let sum = v1+v2;
// return sum;
// }
let sumvalue = (v1,v2)=>{
let sum = v1+v2;
return sum;
}
console.log(sumvalue(10,20));
//箭头函数+解构表达式 可以直接结构person对象的name 达到简化代码
let hello = ({name})=>{console.log({name})};
hello(person);
//对象
let iphone={
version:'p6',
show:function(obj){
console.log('顾客'+obj+'您型号是'+this.version);
},
//省掉了function
show2(obj){
console.log('顾客'+obj+'您的型号是'+this.version);
},
//使用箭头函数不能用this,要用对象本身
show3: obj =>{
console.log('顾客'+obj+'您的型号是'+iphone.version);
}
}
iphone.show(name);
iphone.show2(name);
iphone.show3(name);
//合并对象
let hebing ={...person,...iphone};
console.log(hebing)
//循环每一个元素
let score = ['60','70','80','90'];
//map完整写法
// score = score.map((item)=>{
// return item = item*20;
// })
// //单个参数可以简写为
score = score.map(item=>item*20);
console.log(score)
//循环每一个元素带回调
score = score.reduce((a,b)=>{
console.log("上一个请求"+a);
console.log("当前正在处理"+b);
return a+b;
})
console.log(score)
//Pormise 异步封装请求
function get(url,data){
return new Promise((resolve,reject)=>{
$.ajax({
url:url,
data:data,
success:function(data){
resolve(data)
},
error:function(error){
reject(error)
}
})
});
}
get("user.json").then((data) => {
console.log(data)
})
.catch((erro)=>{
console.log(erro)
});
// class类
class Person{
constructor(name){ //构造函数
this.name=name;
}
sayName(){
console.log('name: '+this.name);
}
}
var stu = new Person('jack');
stu.sayName();
// ?? 运算符被称为非空运算符。如果第一个参数不是 null/undefined，将返回第一个参数，否则返回第二个参数
console.log(null ?? 5) // => 5
console.log(2 ?? 5) // => 2
function fn(obj){
var a = obj ?? {};
console.log(a);
}
// 等价于
// function fn(obj){
// var a;
// if( obj === null || obj === undefined){
// a = {}
// } else {
// a = obj;
// }
// console.log(a);
// }
</script>
<script type="module">
import aa from '/tool.js';
let value = aa.sum(10,30);
console.log("模块计算结果"+value);
</script>
