Es6

数组展开运算符

    console.log(...[1,2,3,4])  //1,2,3,4
    
    //合并数组
    const a = [1,2]
    const b = [3,4,5]
    conosle.log([...a,...b])
    
    //将字符串转换成数组
    let str = 'ljc'
    console.log([...str])
    

剩余参数

    const add = (a,b,...arg)=>{
        console.log(arg)   //[3,4,5]
    }
    add(1,2,3,4,5)

对象展开运算符

    合并对象
    const obj1 = {
        name:'小明'
    }
    const obj2 = {
        age:18
    }
    console.log({...obj1,...obj2}) //{name:'李嘉诚',age:18}

Set

Set是什么（集合）

    //声明
    const s = new Set() 

Set参数

    const s = new Set([1,2,3])
    const s = new Set('hello')