Found 6686 Articles for Javascript

Iterate over an object and remove false property in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:37:36

1K+ Views

Suppose, we have a JSON object like this −const obj = {    a: {       someKey: {          propOne: '',          enabled: true       }    },    b: {       someKey: {          propOne: '',          enabled: false       }    },    c: {       someKey: {          propOne: '',          enabled: false       }    },    someKey: {       ab: {     ... Read More

Center of each side of a polygon in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:34:32

121 Views

Suppose, we array of arrays like this −const arr = [    [-73.9280684530257, 40.8099975343718],    [-73.9282820374729, 40.8100875554645],    [-73.9280124002104, 40.8103130893677],    [-73.927875543761, 40.8102554080229],    [-73.9280684530257, 40.8099975343718] ];Here each subarray represents a point on a 2-D plane, and each point is a vertex of n sided polygon where n is the number of subarrays in the input arrays.We are required to write a JavaScript function that takes in one such array and returns a new array of n subarrays, each representing the midpoint of corresponding sides of the polygon.ExampleThe code for this will be −const arr = [    [-73.9280684530257, 40.8099975343718],    [-73.9282820374729, 40.8100875554645],    [-73.9280124002104, 40.8103130893677],    [-73.927875543761, 40.8102554080229],    [-73.9280684530257, 40.8099975343718] ]; const findCenters = arr => {    const centerArray = [];    for(i = 0; i

Combine two different arrays in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:32:20

302 Views

Suppose we have two arrays, the first array contains the scheduled date for some events and the second array contains the names of those events, like this −const dates = [    {       id:"1",       date:"2017-11-07"    },    {       id:"1",       date:"2017-11-08"    },    {       id:"2",       date:"2017-11-07"    },    {       id:"2",       date:"2017-11-08"    } ]; const names = [    {       id:"1",       name:"Pervies, Peter"    },    {   ... Read More

Finding number of occurrences of the element appearing most number of times in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:26:58

351 Views

We are required to write a JavaScript function that takes in an array of literals and returns the count of elements that appears for the most number of times in the array.ExampleThe code for this will be −let arr = [2, 8, 4, 8, 6, 4, 7, 8]; const countOccurence = arr => {    const max = arr.reduce((acc, val) => {       return Math.max(acc, val);    }, -Infinity);    const count = arr.filter(el => {       return el === max;    });    const { length } = count;    return length; }; console.log(countOccurence(arr));OutputThe output in the console −3

How to filter out common array in array of arrays in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:25:35

191 Views

Suppose we have an array of arrays like this −const arr = [    [       "Serta",       "Black Friday"    ],    [       "Serta",       "Black Friday"    ],    [       "Simmons",       "Black Friday"    ],    [       "Simmons",       "Black Friday"    ],    [       "Simmons",       "Black Friday"    ],    [       "Simmons",       "Black Friday"    ] ];We are required to write a JavaScript function that ... Read More

Sort an array according to another array in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:22:53

260 Views

Suppose we have two arrays of literals like these −const arr1 = [1, 3, 2, 4, 5, 6]; const arr2 = [1, 2, 5];We are required to write a JavaScript function that takes in two such arrays. Then our function should return a new array that contains all the elements of arr1 but sorted according to arr2.Like the elements that appear in both the array should appear first according to their order in the second array followed by the elements only present in first array retaining their order.ExampleThe code for this will be −const arr1 = [1, 3, 2, 4, ... Read More

Removing duplicate objects from array in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:20:43

219 Views

Suppose, we have an array of objects like this −const arr = [    {"title": "Assistant"},    {"month": "July"},    {"event": "Holiday"},    {"title": "Assistant"} ];We are required to write a JavaScript function that takes in one such array. Our function should then return a new array that contains all the object from the original array but the duplicate ones.ExampleThe code for this will be −const arr = [    {"title": "Assistant"},    {"month": "July"},    {"event": "Holiday"},    {"title": "Assistant"} ]; const removeDuplicate = arr => {    const map = {};    for(let i = 0; i < ... Read More

Remove element from array referencing spreaded array in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:18:51

169 Views

Suppose we have an array of literals like this −const arr = ['cat', 'dog', 'elephant', 'lion', 'tiger', 'mouse'];We are required to write a JavaScript function that takes in one such array as the first argument and then any number of strings as second and third and many more arguments.Then our function should remove all the strings from the array taken as first argument in place if that string is provided as argument to the function.ExampleThe code for this will be −const arr = ['cat', 'dog', 'elephant', 'lion', 'tiger', 'mouse']; const removeFromArray = (arr, ...removeArr) => {    removeArr.forEach(item => { ... Read More

How to merge two strings alternatively in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:17:20

937 Views

We are required to write a JavaScript function that takes in two. Our function should then return a new array that contains characters alternatively from both the strings.For example: If the two strings are −const str1 = 'abc'; const str2 = 'def';OutputThen the output should be −const output = 'adbecf';ExampleThe code for this will be −const str1 = 'abc'; const str2 = 'def'; const mergeAlternatively = (str1, str2) => {    const a = str1.split("").filter(el => !!el);    const b = str2.split("");    let mergedString = '';    for(var i = 0; i < a.length || i < b.length; i++){ ... Read More

Removing duplicate values in a twodimensional array in JavaScript

AmitDiwan
Updated on 12-Oct-2020 11:15:55

1K+ Views

We are required to write a JavaScript function that takes in a two-dimensional array of literals.Our function should return a new array that contains all the entries from the original array but the repeating ones.ExampleThe code for this will be −const arr = [    [1,2,3,4,5],    [3,4,6,7,8,2],    [7,2,4,9,11,15],    [10,12,3,7,11] ]; const removeDuplicates = arr => {    let map = {};    let res = [];    res = arr.map(el => {       return el.filter(val => {          if(map[val]){             return false;          };          map[val] = 1;          return true;       });    });    return res; }; console.log(removeDuplicates(arr));OutputThe output in the console −[ [ 1, 2, 3, 4, 5 ], [ 6, 7, 8 ], [ 9, 11, 15 ], [ 10, 12 ] ]

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