js & Array to Set

[xgqfrms]

js & Array to Set

// js & Array to Set
let arr = [1, 2, 3, 3, 4, 5];
console.log(`arr =`, arr);

const set = new Set(arr);
console.log(`set =`, set);
console.log(`[...set] =`, [...set]);

https://codepen.io/xgqfrms/pen/jgmzYd

---

demo

let oldData = [1, 2, 3];

let newData = [3, 4, 5];

let data = oldData.concat(newData);
// (6) [1, 2, 3, 3, 4, 5]

// Array to Set
data = [...(new Set(data)];
// VM437:2 Uncaught SyntaxError: Unexpected token ]

let temp = new Set(data);
// Set(5) {1, 2, 3, 4, 5}

data = [...temp];
// (5) [1, 2, 3, 4, 5]

[xgqfrms]

js & Array to Set

filter & unique item

https://stackoverflow.com/questions/28965112/javascript-array-to-set

Set

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set

let arr = [1, 2, 3, 3, 4, 5];
console.log(`arr =`, arr);

const set = new Set(arr);
console.log(`set =`, set);
console.log(`[...set] =`, [...set]);

[xgqfrms]

[xgqfrms]

object bug

let newData = [{K: 3}, {K: 4}, {K: 5}];
// (3) [{…}, {…}, {…}]

let oldData = [{K: 3}, {K: 2}, {K: 1}];
// (3) [{…}, {…}, {…}]

data = oldData.concat(newData);
// (6) [{…}, {…}, {…}, {…}, {…}, {…}]0: {K: 3}1: {K: 2}2: {K: 1}3: {K: 3}4: {K: 4}5: {K: 5}length: 6__proto__: Array(0)

temp = new Set(data);
// Set(6) {{…}, {…}, {…}, {…}, {…}, …}size: (...)__proto__: Set[[Entries]]: Array(6)0: Objectvalue: {K: 3}1: value: {K: 2}2: value: {K: 1}3: Object4: Object5: Objectlength: 6

data = [...temp];
(6) [{…}, {…}, {…}, {…}, {…}, {…}]

object array filter unique

https://stackoverflow.com/questions/15125920/how-to-get-distinct-values-from-an-array-of-objects-in-javascript

remove duplicate objects from an array

https://reactgo.com/removeduplicateobjects/

https://dev.to/saigowthamr/how-to-remove-duplicate-objects-from-an-array-javascript-48ok

https://dev.to/vuevixens/removing-duplicates-in-an-array-of-objects-in-js-with-sets-3fep

https://gist.github.com/telekosmos/3b62a31a5c43f40849bb

[xgqfrms]

"use strict";

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 *
 * @description getUniqueObjects
 * @augments
 * @example
 * @link
 *
 */

const getUniqueObjects = (arr = [], key = ``, debug = false) => {
    let result = [];
    result = arr.map(e => e[key])
        // store the keys of the unique objects
        .map((e, i, final) => final.indexOf(e) === i && i)
        // eliminate the dead keys & store unique objects
        .filter(e => arr[e]).map(e => arr[e]);
    return result;
};

export default getUniqueObjects;

export {
    getUniqueObjects,
};

/*

function getUnique(arr, comp) {
    const unique = arr
        .map(e => e[comp])
        // store the keys of the unique objects
        .map((e, i, final) => final.indexOf(e) === i && i)
        // eliminate the dead keys & store unique objects
        .filter(e => arr[e]).map(e => arr[e]);
    return unique;
}

*/

https://dev.to/saigowthamr/how-to-remove-duplicate-objects-from-an-array-javascript-48ok

[xgqfrms]

OK

"use strict";

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 *
 * @description getUniqueObjects
 * @augments
 * @example
 * @link
 *
 */

const getUniqueObjects = (arr = [], key = ``, debug = false) => {
    let log = console.log;
    let result = [];
    result = arr.map(e => e[key])
        // store the keys of the unique objects
        .map((e, i, final) => final.indexOf(e) === i && i)
        // eliminate the dead keys & store unique objects
        .filter(e => arr[e]).map(e => arr[e]);
    if (debug) {
        log(`arr =`, JSON.stringify(arr, null, 4));
        log(`result =`, JSON.stringify(result, null, 4));
    } else {
        log(`arr.length =`, arr.length);
        log(`result.length =`, result.length);
    }
    return result;
};

export default getUniqueObjects;

export {
    getUniqueObjects,
};

[xgqfrms]

"use strict";

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 *
 * @description getUniqueObjects
 * @augments
 * @example
 * @link
 *
 */

const getUniqueObjects = (arr = [], key = ``, debug = false) => {
    let log = console.log;
    let result = [];
    result = arr.map(e => e[key])
        .map((e, i, final) => final.indexOf(e) === i && i)
        .filter(e => arr[e])
        .map(e => arr[e]);
    if (debug) {
        log(`arr =`, JSON.stringify(arr, null, 4));
        log(`result =`, JSON.stringify(result, null, 4));
    } else {
        log(`arr.length =`, arr.length);
        log(`result.length =`, result.length);
    }
    return result;
};

export default getUniqueObjects;

export {
    getUniqueObjects,
};