Question

suppose i have an array in Javascript with several objects in it.

var data = [

{

name: Jack,

mobile: 1234,

date: 2019-01-15 13:42:11},

}

{

name: Jack,

mobile: 1234,

date: 2019-01-13 10:35:55},

}

{

name: Jack,

mobile: 1234,

date: 2019-01-13 9:20:55},

}

{

name: Mike,

mobile: 1234,

date: 2019-01-13 12:35:55},

}

{

name: Mike,

mobile: 1234,

date: 2019-01-13 9:30:55},

}

{

name: Mike,

mobile: 1234,

date: 2019-01-13 05:25:55}

how to make a function that takes this array and returns the new array with objects, that only have the latest date. Notice that each object( name) has arrived at different time. so for each name, need the latest time to arrive

Answer 1

Code - Javascript

/* object array */

var data = [

    {

        "name": "Jack",

        "mobile": "1234",

        "date": "2019-01-15 13:42:11"

    },

    {

        "name": "Jack",

        "mobile": "1234",

        "date": "2019-01-13 10:35:55"

    },

    {

        "name": "Jack",

        "mobile": "1234",

        "date": "2019-01-13 9:20:55"

    },

    {

        "name": "Mike",

        "mobile": "1234",

        "date": "2019-01-13 12:35:55"

    },

    {

        "name": "Mike",

        "mobile": "1234",

        "date": " 2019-01-13 9:30:55"

    },

    {

        "name": "Mike",

        "mobile": "1234",

        "date": "2019-01-13 05:25:55"

    }]

/* function call filterArray */

filterArray(data);

/* it take json object as arguement */

function filterArray(data) {

    let maxDate;

    /* get the max date of Jack  uding filter and reduce fucntion javascript*/

    maxDateJack = data.filter((d) => d.name === "Jack").

        reduce((acc, prev) => {

            if (new Date(acc.date) > new Date(prev.date)) {

                maxDate = acc.date;

            }

            return maxDate;

        })

    console.log(maxDateJack)

    let maxDateMike;

    /* get the max date of Mike */

    maxDateMike = data.filter((d) => d.name === "Mike").

        reduce((acc, prev) => {

            if (new Date(acc.date) > new Date(prev.date)) {

                maxDateMike = acc.date;

            }

            return maxDateMike;

        })

    console.log(maxDateMike)

    /* get the max date of Jack and Mike using filter*/

    filterDate = data.filter((d) => {

        if (d.date == maxDateJack || d.date == maxDateMike) {

            return d;

        }

    })

    console.log(filterDate)

    return filterDate;

}