學(xué)會lambda----------------------珍惜生命少寫代碼！

1.map() ，改變list

<script>

    let oldList = [{name:'ZhangSan',age:18},{name:'LiSi',age:20}]
    let newList = oldList.map(i=>  {
        return   {name:i.name,size:i.age,sex:'man'}
    })
    // 名字不變 age變成size 再加個sex都為man
    console.log(oldList)
    console.log(newList)

</script>

2.es6解構(gòu)

<script>
    let {length : len1} = 'hello';     // len1 =  5
    let x = 1
    let y = 2;
    //es6解構(gòu) x y 交換值
    [x, y] = [y, x]
    console.log('x=',x)
    console.log('y=',y)

</script>