从 Javascript 中的每一列获取最大值？

Question

我在 Javascript 工作。我有一组对象。每个对象看起来像这样{    date: Mon Oct 31 2016 19:00:00 GMT-0500 (Central Daylight Time),     Catan: 62588,     Dominion: 51915,     Codenames: 21263,     Terraforming Mars: 2148}如何从第 2-5 列获取最大数字的数组？

Answer 1

首先映射以获取每个对象的 col2-5 值数组，然后减少它以找到相应列的最大值

const data = [

  {

    date: "Mon Oct 31 2016 19:00:00 GMT-0500 (Central Daylight Time)",

    Catan: 62588,

    Dominion: 51915,

    Codenames: 21263,

    "Terraforming Mars": 2148,

  },

  {

    date: "Mon Oct 31 2016 20:00:00 GMT-0500 (Central Daylight Time)",

    Catan: 9561,

    Dominion: 74152,

    Codenames: 5123,

    "Terraforming Mars": 1078,

  },

  {

    date: "Mon Oct 31 2016 21:00:00 GMT-0500 (Central Daylight Time)",

    Catan: 62588,

    Dominion: 84102,

    Codenames: 96396,

    "Terraforming Mars": 6423,

  },

]

const res = data

  .map((obj) => Object.values(obj).slice(1, 5))

  .reduce((acc, el) => acc.map((max, i) => Math.max(max, el[i])), [0, 0, 0, 0])

console.log(res)

Answer 2

要从您的对象中获取最大值，请尝试以下操作：

let foo = {

    date: "Mon Oct 31 2016 19:00:00 GMT-0500 (Central Daylight Time)", 

    Catan: 62588, 

    Dominion: 51915, 

    Codenames: 21263, 

    "Terraforming Mars": 2148

};

let arr = Object.keys(foo).map(function(key) { return foo[key] });

arr.shift()

let max = Math.max.apply(null, arr);

console.log(max); // prints 62588

请注意，我必须对您最初发布的对象进行一些更改，因为它不是有效的 javascript。

Answer 3

不是 100% 确定我理解这个要求，但是如果你正在寻找数组中保存的对象的最大值，那么这样的事情可能会起作用。

let dataArray = [

{ID: "object1", firstValue:7, secondValue:1},

{ID: "object2", firstValue:3, secondValue:10}

]

let maxFirstValue = 0;

let maxSecondValue = 0;

for (let i = 0; i< dataArray.length; i++){

  if (dataArray[i].firstValue > maxFirstValue) {maxFirstValue = dataArray[i].firstValue}

  if (dataArray[i].secondValue > maxSecondValue) {maxSecondValue = dataArray[i].secondValue}

}

let resultsObject = {firstValue: maxFirstValue, secondValue: maxSecondValue}

console.log(resultsObject);

Answer 4

function getColumns(object){

    //columns:

    const columns = [];

    

    const keys = Object.keys(object[Object.keys(object)[0]]);

    keys.forEach(key => columns.push([]));

    /* keys.shift(); //because you don't want the "date" */

    

    let i = 0; // to move between the arrays of "columns"

    for(id in object){

        keys.forEach(key => {

            console.log(i, key, object[id][key]);

            columns[i].push(object[id][key]);

            i++;

        })

        console.log("-----------");

        i = 0;

    }

    

    return columns;

    }

    

    function MathMaxes(array){

        //is a private function for you <3

        const result = array.map(column=> Math.max(...column));

        return result;

    }

//the testing object

const data = {

    1:{

        date: "Mon Oct 31 2016 19:00:00 GMT-0500 (Central Daylight Time)", 

        Catan: 23432, 

        Dominion: 2233, 

        Codenames: 111, 

        "Terraforming Mars": 2344

    },

    2:{

        date: "Mon Oct 31 2016 19:00:00 GMT-0500 (Central Daylight Time)", 

        Catan: 1123, 

        Dominion: 353, 

        Codenames: 54645, 

        "Terraforming Mars": 2333

    },

    3:{

        date: "Mon Oct 31 2016 19:00:00 GMT-0500 (Central Daylight Time)", 

        Catan: 34673, 

        Dominion: 34532, 

        Codenames: 6457, 

        "Terraforming Mars": 1231

    }

}

const columns = getColumns(data);

columns.shift(); //because you don't want the dates

const theMaxes = MathMaxes(columns);

console.log(theMaxes);

Answer 5

let foo = [{

date: "Mon Oct 31 2016 19:00:00 GMT-0500 (Central Daylight Time)", 

Catan: 0, 

Dominion: 1, 

Codenames: 2, 

"Terraforming Mars": 3

},

{

date: "Mon Oct 31 2016 19:00:00 GMT-0500 (Central Daylight Time)", 

Catan: 3, 

Dominion: 2, 

Codenames: 1, 

"Terraforming Mars": 0

}

];

foo = foo.map(column => {

   let keys = Object.keys(column);

   let max = -1;

   let targetKey = '';

   keys.forEach(( keyName, index ) => {

       if(index > 0){

         if(column[keyName] > max){

            max = column[keyName];

            targetKey = keyName;

         }

       }

   })

   return {value: max, key: targetKey}

});

console.log("foo", foo);

请让我知道这可不可以帮你。

预期结果

[

 {

  value: 3,

  key: "Terraforming Mars"

 },

 {

  value: 3,

  key: "Catan"

 }

]