reduce的应用

 let testData=[{
        num:45,
        name:'第一'
    },{
        num:23,
        name:'第二'
    },{
        num:12,
        name:'第二'
    }];
    let data=[0,12,45]

    let test= testData.reduce((a,b)=>{
        return a+b.num // 注意是b的参数
    },0)
    let dd=data.reduce((a,b)=>{
        return a+b
    })
    console.log(test); //80
    console.log(dd); //57

详情文章借鉴https://www.jianshu.com/p/e375ba1cfc47