ES6 数组map()，创建新数组

后端返回的原始数组

let  techerList = [
  {techerId:'t1',techerName:'张三',sex:'男',email:'123456789@qq.com'},
 {techerId:'t2',techerName:'李四',sex:'女',email:'123456789@qq.com'},
 {techerId:'t3',techerName:'王五',sex:'男',email:'123456789@qq.com'},
 {techerId:'t4',techerName:'赵六',sex:'女',email:'123456789@qq.com'},
 {techerId:'t5',techerName:'孙七',sex:'男',email:'123456789@qq.com'}
]

只需要一个单独的属性

let newTecherList = techerList.map(item=>{
            return item.techerId
        })
console.log(newTecherList);   //返回数组["t1","t2","t3","t4","t5",]

需要多个属性

let newTecherList1 = techerList.map(item=>({
            techerId:item.techerId,
            techerName:item.techerName,
        }))
console.log(newTecherList1); //返回数组[{techerId: "t1", techerName: "张三"},...]

map返回的是一个新的数组