1、查詢是否包含贏一個字符串
'xxxx'.includes(x,i);//x子字符串，i起始位置
2、forEach（數(shù)組的循環(huán)不能中斷）

array.forEach(function(currentValue,index,array){}) 
//必須 currentValue: 當(dāng)前的元素
//可選 index：當(dāng)前元素的索引值
//可選 array: 當(dāng)前元素所屬的數(shù)組對象

3、創(chuàng)建類

class Human {
    constructor(name) {
        this.name = name;
    }
    breathe() {
        console.log(this.name + " is breathing");
    }
}
var human = new Human("yancy");
human.breathe();//yancy is breathing

//繼承
class Man extends Human {
    constructor(name,sex){
        super(name);//es6語法 訪問父級對象上的構(gòu)造函數(shù)
        this.sex = sex;
    }
    info(){
        console.log(`${this.name} is ${this.sex}`);
    }
}
var man = new Man('henry','boy');
man.breathe();//henry is breathing
man.info();//henry is boy

4、箭頭函數(shù)

var arr = ['A', '', 'B', null, undefined, 'C', '      '];//刪掉空字符串
var newArr = arr.filter( val => (val && val.trim()));//newArr = ['A','B','C']