js数组reduce累计方法

reduce的作用是累计器，返回累计处理的结果，经常用于求和等

基本语法：arr.reduce(function(){},初始值)

没有初始值

        const arr=[1,5,8]
        const total=arr.reduce((prev,current)=> prev + current,)
        console.log(total)//total=14

有初始值，会影响最终的结果

        const total1=arr.reduce((prev,current)=> prev+current,10)
        console.log(total1)//total1=24

计算薪资案例

        const workers=[{name:'小张',salary:10000},{name:'小李',salary:12000},{name:'小明',salary:13000}]
        const expenditure=workers.reduce((prev,current)=>{
            return prev+current.salary
        },0)
        console.log(expenditure)// expenditure=35000