ES6,ES7重点介绍

悠悠 2022-02-01 11:11 276阅读 0赞

1. 字符串模板  
    
    var str = '我是时间:'+new Date();
    
    let str = `我是时间${new Date()}`;
    
    
    2. 对象简写
    
    var name = "liming";
    var age = 20;
    var person = {name:name, age:age};
    
    let name = "liming";
    let age = 20;
    let person = {name, age};
    
    
    3. 箭头函数
    
    setTimeout(function(res){
        alert(res)
    },50)
    采用箭头函数后的写法
    setTimeout((res) => {
        alert(res)
    })
    
    
    4. 模块化
    export 导出模块
    import 导入模块
    
    
    5. 解构
    
    let arr = ['string', 2, 3];
    //传统方式
    let a = arr[0],
        b = arr[1],
        c = arr[2];
    //解构赋值，是不是简洁很多？
    let [a, b, c] = arr;
    console.log(a);
    console.log(b);
    console.log(c);
    
    
    let arr = [[1, 2, [3, 4]], 5, 6];
    let [[d, e, [f, g]], h, i] = arr;
    console.log(d);
    console.log(f);
    console.log(i);
    
    
    var arr = ['string', 2, 3]
    function fn1([a, b, c]) {
        console.log(a);
        console.log(b);
        console.log(c);
    }
    fn1(arr);
    
    
    
    
    
    
    6. Promise
    
    new Promise((resolve,reject) => {
        
    })
    .then((res) =>{})
    .catch((err) =>{})

async await 讲解

[一眼看懂promise async][promise async]

1. includes  
    
    
    let s = 'Hello world!';
    s.includes('o') // true
    
    2. repeat()

1.最常见的循环
    
    let array = [1, 2, 3, 4];
    array.forEach((item, index, arr) => {
    　　console.log(item);
    });
    
    
    
    
    
    
    let array = [1, 2, 3, 4 ,5];
    let temp = array.map((item, index, arr) => {
        return item + 1;
    });
    
    
    
    let array = [{name:'liming'},{name:'zhangsan'},{name:'wangwu'}]
    let newArray = array.map((item, index, arr) => {
        return {'姓名':`${item.name}***`}
    })
    console.log(newArray);
    
    
    
    
    
    
    let array = [100, 25, 35, 98, 67];
    array.some((item, index, arr) => {
        return item < 60 ;
    });
    
    
    2.filter
    
    let array = [1, 2, 3, 4, 5];
    let temp = array.filter((item, index, arr) => {
        return item > 3;    
    });
    console.log(temp);
    console.log(array);
    3.reduce
    
    
    let array = [1, 2, 3, 4, 5];
    let total = array.reduce((a, b) => {
        return a + b;
    });
    console.log(total);     
    
    4. 还有类似于array.keys(),array.values()等就不多说了

[promise async]: https://www.cnblogs.com/zddzz/p/10831668.html