SOURCE

// 改方法可去重 合并
var arrA = [
    { id: 1, name: '张三' },
    { id: 1, name: '张三' },
    { id: 2, name: '李四' },
    { id: 1, age: 12 },
    { id: 1, age: 12 },
    { id: 2, age: 18 }
]

let newArr = arrA.reduce((ret, item) => {
    if (ret.some(rei => { return rei.id === item.id })) {
        ret.forEach(o => {
            if (o.id === item.id) {
                Object.assign(o, item)
            }
        })
        return ret
    }
    return ret.concat(item)
}, [])
//console.log(newArr)


// 递归深拷贝
var obj = {
    name: 'Mr.YANG',
    sex: '男',
    age: 18,
    arr: [12, 34, 56, 78, 90],
    arrb: [
        {id:1},
        {id:2},
        {id:3},
        {id:4},
        {id:5}
    ],
    body: {
        height: '180cm',
        weight: '70kg'
    }
}

function deepClone(obj) {
    var newObj = null
    if (typeof (obj) === 'object' && typeof (obj) !== null) {
        newObj = obj instanceof Array ? [] : {}
        for (var i in obj) {
            newObj[i] = deepClone(obj[i])
        }
    } else {
        newObj = obj
    }
    return newObj
}
//console.log(deepClone(obj))

var deepArr = [1, 2, [3, 4, [5, 6]], 7, [8, 9, [10]]]

function handArr(arr) {
    return arr.reduce((ret, item) => {
        return ret.concat(Array.isArray(item) ? handArr(item) : item)
    }, [])
}

// 数组扁平化与去重

var beforArr = [1, 2, [3, 4, 5, 1, [2, 5, 6, [7, 5, 6]]], 8, [9, 3], 10]

function handArr(arr) {
    return arr.reduce((ret, item) => {
        return ret.filter((itm, index, arry) => { return arry.indexOf(itm) === index }).concat(Array.isArray(item) ? handArr(item) : item)
    }, [])
}
// console.log(handArr(beforArr))

//取平均值

var countArr = [1, 2, 3, 4, 5, 6, 7, 8, 9]

function handCount(arr) {
    return arr.reduce((ret, item, index, restArr) => {
        if(index === restArr.length - 1){
           return ret / restArr.length
        }
        return ret + item
    }, 0)
}
// console.log(handCount(countArr))