Javascript: Split Array of Objects into Seperate Arrays With Dynamic Names Depending on Property Value

Javascript: Split array of objects into seperate arrays with dynamic names depending on property value

You can simply achieve your desired outcome using reduce, as you can produce an object using reduce, here's an example of how you could do it.

As you can see, it'll check that the relevant property on the object isn't null, if it is, then it's set to an empty array, after this check, it's safe to simply push the relevant values onto the array, like so.

var array = [{    slotStarttime: "06:00:00",    slotTimespan: 1  },  {    slotStarttime: "09:00:00",    slotTimespan: 1  },  {    slotStarttime: "12:00:00",    slotTimespan: 2  },  {    slotStarttime: "15:00:00",    slotTimespan: 2  },  {    slotStarttime: "18:00:00",    slotTimespan: 3  }];
var newObject = array.reduce(function(obj, value) {  var key = `timespan${value.slotTimespan}`;  if (obj[key] == null) obj[key] = [];
  obj[key].push(value);  return obj;}, {});
console.log(newObject);

How to split an Array of Objects into another Arrays based on their values?

Although it's possible to create global variables with dynamic names, it's not possible to create non-global variables with dynamic names, and the global environment is already sufficiently crowded that creating a bunch of new globals is not best practice.

Instead, use a Map:

const playerArrays = new Map();
for (const entry of database) {
    const key = `player${entry.player}`;
    const array = playerArrays.get(key);
    if (!array ) {
        // Haven't seen this one yet, add a new array
        playerArrays.set(key, [entry]);
    } else {
        // We have the array, add to it
        array.push(entry);
    }
}

Then you get an individual array by using playerArrays.get("player1") and such.

Live Example:

var database = [{
    player: 1,
    level: 1,
    score: 20
  },
  {
    player: 2,
    level: 1,
    score: 25
  },
  {
    player: 3,
    level: 1,
    score: 7
  },
  {
    player: 1,
    level: 2,
    score: 25
  },
  {
    player: 2,
    level: 2,
    score: 7
  }
];

const playerArrays = new Map();
for (const entry of database) {
    const key = `player${entry.player}`;
    const array = playerArrays.get(key);
    if (!array ) {
        // Haven't seen this one yet, add a new array
        playerArrays.set(key, [entry]);
    } else {
        // We have the array, add to it
        array.push(entry);
    }
}
console.log("player1:", playerArrays.get("player1"));

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Split array with objects to multiple arrays based on unique combination

Another short Array.prototype.reduce() approach:

var dataset = [  {time: "t1", locA: "a1", locB: "b1", value: "v1"}, {time: "t1", locA: "a1", locB: "b2", value: "v2"}, {time: "t1", locA: "a2", locB: "b1", value: "v3"},   {time: "t1", locA: "a2", locB: "b2", value: "v4"}, {time: "t2", locA: "a1", locB: "b1", value: "v5"}, {time: "t2", locA: "a1", locB: "b2", value: "v6"}, {time: "t2", locA: "a2", locB: "b1", value: "v7"}, {time: "t2", locA: "a2", locB: "b2", value: "v8"}];
var result = dataset.reduce(function(r, o){    var k = o.locA + o.locB;   // unique `loc` key    if (r[k] || (r[k]=[])) r[k].push({loc:k, time: o.time, value: o.value});    return r;}, {});
console.log(result);

How to split array dynamically based on single value in JavaScript Node.js

You could use an object with the grouped items. It works for any tags and allows a list of all tags with Object.keys(grouped), if required.

var dataStuff = [{ Name: 'Apple', Tag: 'Fruit', Price: '2,5' }, { Name: 'Bike', Tag: 'Sport', Price: '150' }, { Name: 'Kiwi', Tag: 'Fruit', Price: '1,5' }, { Name: 'Knife', Tag: 'Kitchen', Price: '8' }, { Name: 'Fork', Tag: 'Kitchen', Price: '7' }],    grouped = Object.create(null);
dataStuff.forEach(function (a) {    grouped[a.Tag] = grouped[a.Tag] || [];    grouped[a.Tag].push(a);});
document.write(Object.keys(grouped));document.write('<pre>' + JSON.stringify(grouped, 0, 4) + '</pre>');

Split array into chunk of different size on the basis of their attribute

You can simply use Array.reduce() to group items by semester. Object.values() on the map gives you the desired result.

var array=[{ semster:1, name:"Book1" }, { semster:1, name:"Book2" }, { semster:2, name:"Book4" }, { semster:3, name:"Book5" }, { semster:3, name:"Book6" }, { semster:4, name:"Book7" }];
var result = Object.values(array.reduce((a, curr)=>{  (a[curr.semster] = a[curr.semster] || []).push(curr);  return a;},{}));
console.log(result);

split an array into two based on condition using javascript

You could take an array and push the objects according their availability with a single loop.

const
    data = [{ product_id: 4, product_name: "Samsung", category_name: "Tv and home appliance", is_Available: 1 }, { product_id: 8, product_name: "Apple", category_name: "Home gadgets", is_Available: 1 }, { product_id: 9, product_name: "Verifone", category_name: "Electronics", is_Available: 0 }],
    result = data.reduce((r, o) => {
        r[o.is_Available ? 'availableData' : 'notAvailableData'].push(o);
        return r;
    }, { availableData: [], notAvailableData: [] });

console.log(result);

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Javascript: Split Array of Objects into Seperate Arrays With Dynamic Names Depending on Property Value