js的数组排序sort

1.默认--按照ASCII码进行升序排序

arr.sort()

2.自定义排序方式--a和b是相邻的两个数,a在前,b在后.如果返回正数，则a，b交换位置，负数和零则不变，所以也适用于json

arr.sort((a,b)=>{})//1.升序 if(a>b){  return 1}else{return -1}//2.降序if(a<b){  return 1}else{return -1}//如果a,b是数字则可简写 return a-b  //升序return b-a  //降序

3.json
按照name升序

arr=[{id:1,name:'a'},{id:2,name:'b'},{id:3,name:'c'},{id:4,name:'d'}]arr.sort((a,b)=>{  if(a.name>b.name){      return 1    }else{return -1}})

按照name降序

arr=[{id:1,name:'a'},{id:2,name:'b'},{id:3,name:'c'},{id:4,name:'d'}]arr.sort((a,b)=>{  if(a.name<b.name){      return 1    }else{return -1}})