Found 6710 Articles for Javascript

How to convert an array into a complex array JavaScript?

AmitDiwan
Updated on 26-Aug-2020 11:47:16

311 Views

Let’s say, we are required to write a function that takes in an array of Numbers and number n, where n >= any number of the array. The function is required to break the array into subarrays if the sum of consecutive elements of the array exceeds the number n.For example −// if the original array is: const arr = [2, 1, 2, 1, 1, 1, 1, 1]; // and the number n is 4 // then the output array should be: const output = [ [ 2, 1 ], [ 2, 1, 1 ], [ 1, 1, 1 ] ... Read More

Remove duplicates from an array keeping its length same in JavaScript

AmitDiwan
Updated on 26-Aug-2020 11:44:56

205 Views

We have to write a function that takes in an array, removes all duplicates from it and inserts the same number of empty strings at the end.For example − If we find 4 duplicate values we have to remove then all and insert four empty strings at the end.Therefore, let’s write the code for this problem −Exampleconst arr = [1, 2, 3, 1, 2, 3, 2, 2, 3, 4, 5, 5, 12, 1, 23, 4, 1]; const deleteAndInsert = arr => {    const creds = arr.reduce((acc, val, ind, array) => {       let { count, res } ... Read More

Finding a greatest number in a nested array in JavaScript

AmitDiwan
Updated on 26-Aug-2020 11:43:04

264 Views

We have to write a simple function in JavaScript that takes in an array of Numbers (nested to any level) and return the greatest number present in the array.For example − If the input array is −const arr = [    34, 65, 67,    [       43, 76, 87, 23, 56, 7,       [          54, 7, 87, 23, 79, 314, 2       ],       54    ], 54, 4, 2 ];Then the output should be −314We will use recursion to find the greatest number in the array. ... Read More

Getting elements of an array depending on corresponding values of another JavaScript

AmitDiwan
Updated on 26-Aug-2020 11:41:41

587 Views

Suppose we have two arrays, for an example consider the following two −const array1 = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']; const array2 = [ 1, 0, 0, 1 , 0, 0, 1, 0];Both the arrays are bound to have the same length. We are required to write a function that when provided with an element from the second array, returns a subarray from the first array of the all elements whose index corresponds to the index of the element we took as an argument in the second array.For example: findSubArray(0) should return −[‘b’, ‘c’, ‘e’, ‘f’, ‘h’]Because ... Read More

Top n max value from array of object JavaScript

AmitDiwan
Updated on 26-Aug-2020 11:39:52

1K+ Views

Let’s say, we have an array of objects like this −const arr = [    {"id":0, "start":0, "duration":117, "slide":4, "view":0},    {"id":0, "start":0, "duration":12, "slide":1, "view":0},    {"id":0, "start":0, "duration":41, "slide":2, "view":0},    {"id":0, "start":0, "duration":29, "slide":3, "view":0},    {"id":0, "start":0, "duration":123, "slide":3, "view":0},    {"id":0, "start":0, "duration":417, "slide":2, "view":0},    {"id":0, "start":0, "duration":12, "slide":1, "view":0},    {"id":0, "start":0, "duration":67, "slide":2, "view":0} ];We have to write a function that takes in this array and returns the top n element of the array in another array (top means the object that has the highest value for duration).Therefore, let’s write the code ... Read More

Count unique elements in array without sorting JavaScript

AmitDiwan
Updated on 26-Aug-2020 11:38:09

355 Views

Let’s say, we have an array of literals that contains some duplicate values −const arr = ['Cat', 'Dog', 'Cat', 'Elephant', 'Dog', 'Grapes', 'Dog', 'Lion', 'Grapes', 'Lion'];We are required to write a function that returns the count of unique elements in the array. Will use Array.prototype.reduce() and Array.prototype.lastIndexOf() to do this −Exampleconst arr = ['Cat', 'Dog', 'Cat', 'Elephant', 'Dog', 'Grapes', 'Dog', 'Lion', 'Grapes', 'Lion']; const countUnique = arr => {    return arr.reduce((acc, val, ind, array) => {       if(array.lastIndexOf(val) === ind){          return ++acc;       };       return acc;    }, 0); }; console.log(countUnique(arr));OutputThe output in the console will be −5

Reorder array based on condition in JavaScript?

AmitDiwan
Updated on 26-Aug-2020 11:35:08

2K+ Views

Let’s say we have an array of object that contains the scores of some players in a card game −const scorecard = [{    name: "Zahir",    score: 23 }, {       name: "Kabir",       score: 13 }, {       name: "Kunal",       score: 29 }, {       name: "Arnav",       score: 42 }, {       name: "Harman",       score: 19 }, {       name: "Rohit",       score: 41 }, {       name: "Rajan",       score: ... Read More

How to create an ordered array from values that have an order number in JavaScript?

AmitDiwan
Updated on 26-Aug-2020 11:30:42

158 Views

Let’s say, we have a series of strings, which contain and image path and order #concatenated. They look like this −const images = [    'photo1.jpg, 0',    'photo2.jpg, 2',    'photo3.jpg, 1' ];Therefore, the correct order should be − photo1, photo3, photo2. What we need to do is process this into a correctly ordered array with just the path values. So, ultimately we need −const orderedImages = [    'photo1.jpg',    'photo3.jpg',    'photo2.jpg' ]Let’s write the code to sort this array of images according to its correct order −Exampleconst images = [    'photo1.jpg, 0',    'photo2.jpg, 2', ... Read More

Merge object & sum a single property in JavaScript

AmitDiwan
Updated on 26-Aug-2020 11:28:30

678 Views

Let’s say, we have two arrays of objects that contain information about some products of a company −const first = [    {       id: "57e7a1cd6a3f3669dc03db58",       quantity:3    },    {       id: "57e77b06e0566d496b51fed5",       quantity:3    },    {       id: "57e7a1cd6a3f3669dc03db58",       quantity:3    },    {       id: "57e77b06e0566d496b51fed5",       quantity:3    } ]; const second = [    {       id: "57e7a1cd6a3f3669dc03db58",       quantity:6    },    {       id: "57e77b06e0566d496b51fed5",     ... Read More

Aggregate records in JavaScript

AmitDiwan
Updated on 26-Aug-2020 11:26:46

2K+ Views

Let’s say, we have an array of objects that contains information about some random transactions carried out by some people −const transactions = [{    name: 'Rakesh',    amount: 1500 }, {       name: 'Rajesh',       amount: 1200 }, {       name: 'Ramesh',       amount: 1750 }, {       name: 'Rakesh',       amount: 2100 }, {       name: 'Mukesh',       amount: 1100 }, {       name: 'Rajesh',       amount: 1950 }, {       name: 'Mukesh',       ... Read More

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