4.排序

4-1升序

arr.sort((a,b)=>{
            return a-b;
        })

4-2降序

 arr.sort((a,b)=>{
            return b-a;
        })

例子
实现数组的排序

 var arr=[4,7,1,3,14];
//升序
arr.sort((a,b)=>{
  return a-b;
})
console.log(arr);//[1,3,4,7,14]
//降序
arr.sort((a,b)=>{
  return b-a;
})
console.log(arr);//[14,7,4,3,1]

实现数组中元素的排序

var students=[
            {name:"zhang",age:20},
            {name:"li",age:18},
            {name:"wang",age:9},
            {name:"陈",age:14},
        ]
        //升序
        var result=students.sort((a,b)=>{
            return a["age"]-b["age"];
        })
        console.log(result);
        //降序
        var result=students.sort((a,b)=>{
            return b["age"]-a["age"];
        })
        console.log(result);

实现指定条件排序

 <button id="like">通过好评数排序</button>
    <button id="price">通过价格排序</button>
    <script>
        var like=document.getElementById("like");
        var price=document.getElementById("price");
        var sales=[
            {name:"张三",like:60,distance:1000,price:10},
            {name:"张三",like:30,distance:100,price:40},
            {name:"张三",like:20,distance:500,price:6},
        ]
        //升序
        function addOrder(arr,value){
            var res=arr.sort((a,b)=>{
                return a[value]-b[value];
            })
            return res;
        }
        like.onclick=function(){
            console.log(addOrder(sales,"like"))
        }
        price.onclick=function(){
            console.log(addOrder(sales,"price"))
        }
    </script>