计算一个数组中key值相同的数量

  // 计算一组数组中key值相同的数量
    let arr = [
        {
            name: 'Mokeke',
            age: 10,
        },
        {
            name: 'caixia',
            age: 10,
        },
        {
            name: 'caixia',
            age: 10,
        },
        {
            name: 'zijian',
            age: 11,
        },
    ]

一、
    function accont(arr) {
        let obj = {}
        for (let i = 0; i < arr.length; i++) {
            if (obj[arr[i].age]) {
                obj[arr[i].age] += 1
            } else {
                obj[arr[i].age] = 1
            }
        }
        return obj
    }
二、
    function accont(arr) {
        let obj = {}
        for (let i = 0; i < arr.length; i++) {
            if (obj[arr[i].age]) {
                obj[arr[i].age] += 1
                continue
            }
            obj[arr[i].age] = 1

        }
        return obj
    }

    let result = accont(arr)
    console.log(result, 'result')
    for(let i in result){
        console.log(`键值为${i}的数量为${result[i]}`)
    }

 

   // 判断数组某一个键值的个数
    function account(text,arr,key){
        debugger
        let temp = {}
        let count = 0
        if(!temp[key]){
            temp[key] = text
            arr.forEach(item => {
                if(item[key] === temp[key]){
                    count += 1
                }
            })
        }
        return count
    }
    let caleResult = account('Mokeke',arr, 'name')
    console.log(caleResult,'count')