Javascript Articles - Page 154 of 534

Retrieving n smallest numbers from an array in their original order in JavaScript

AmitDiwan
Updated on 19-Apr-2021 08:15:19

412 Views

ProblemWe are required to write a JavaScript function that takes in an array of numbers arr, and a number n.Our function should retrieve the n smallest from the array arr without disturbing their relative order. It means they should not be arranged in increasing or decreasing order rather they should hold their original order.ExampleFollowing is the code − Live Democonst arr = [6, 3, 4, 1, 2]; const num = 3; const smallestInOrder = (arr = [], num) => {    if(arr.length < num){       return arr;    };    const copy = arr.slice();    copy.sort((a, b) => a ... Read More

Replacing vowels with their 1-based index in a string in JavaScript

AmitDiwan
Updated on 19-Apr-2021 08:13:22

648 Views

ProblemWe are required to write a JavaScript function that takes in a string and replaces all occurrences of the vowels in the string with their index in the string (1-based).It means if the second letter of the string is a vowel, it should be replaced by 2.ExampleFollowing is the code − Live Democonst str = 'cancotainsomevowels'; const replaceVowels = (str = '') => {    const vowels = 'aeiou';    let res = '';    for(let i = 0; i < str.length; i++){       const el = str[i];       if(vowels.includes(el)){            res += ... Read More

Difference between numbers and string numbers present in an array in JavaScript

AmitDiwan
Updated on 19-Apr-2021 08:06:43

401 Views

ProblemWe are required to write a JavaScript function that takes in a mixed array of number and string representations of integers.Our function should add up okthe string integers and subtract this from the total of the non-string integers.ExampleFollowing is the code − Live Democonst arr = [5, 2, '4', '7', '4', 2, 7, 9]; const integerDifference = (arr = []) => {    let res = 0;    for(let i = 0; i < arr.length; i++){       const el = arr[i];       if(typeof el === 'number'){          res += el;       }else if(typeof el === 'string' && +el){          res -= (+el);       };    };    return res; }; console.log(integerDifference(arr));OutputFollowing is the console output −10

Encoding decimal to factorial and back in JavaScript

AmitDiwan
Updated on 19-Apr-2021 08:04:44

385 Views

ProblemCoding decimal numbers with factorials is a way of writing out numbers in a base system that depends on factorials, rather than powers of numbers.In this system, the last digit is always 0 and is in base 0!. The digit before that is either 0 or 1 and is in base 1!. The digit before that is either 0, 1, or 2 and is in base 2!, etc. More generally, the nth-to-last digit is always 0, 1, 2, ..., n and is in base n!.We will need two functions. The first one will receive a decimal number and return a ... Read More

Finding the product of array elements with reduce() in JavaScript

AmitDiwan
Updated on 19-Apr-2021 08:01:24

968 Views

ProblemWe are required to write a JavaScript function that takes in an array arr. Our function should find and return the product of all the elements of the array.ExampleFollowing is the code − Live Democonst arr = [3, 1, 4, 1, 2, -2, -1]; const produceElements = (arr = []) => {    const res = arr.reduce((acc, val) => {       acc = acc * val;       return acc;    }, 1);    return res; }; console.log(produceElements(arr));OutputFollowing is the console output −48

Encoding a number string into a string of 0s and 1s in JavaScript

AmitDiwan
Updated on 19-Apr-2021 07:56:57

362 Views

ProblemWe are required to write a JavaScript function that takes in a string that represents a decimal number.Our function should convert/encode this decimal into binary based on the following rules.For each digit d of nLet k be the number of bits of dWe write k-1 times the digit 0 followed by the digit 1We write digit d as a binary string, with the rightmost bit being the least significantLastly, we concatenate the result of b) and c) to get the coding of dAt last, we concatenate all the results got for the digits of n.Thus, code 2 as 0110 and ... Read More

Finding reflection of a point relative to another point in JavaScript

AmitDiwan
Updated on 19-Apr-2021 07:41:36

412 Views

Point Of Symmetry"Point reflection" or "point symmetry" is a basic concept in geometry where a given point, P, at a given position relative to a midpoint, Q has a corresponding point, P1, which is the same distance from Q but in the opposite direction.ProblemWe are required to write a JavaScript function that takes in two objects P and Q specifying two points in a 2-D plane.Our function should output the symmetric point of point P about Q.ExampleFollowing is the code − Live Democonst p = {    x: 6, y: -4 }; const q = {    x: 11, y: 5 ... Read More

Performing power operations on an array of numbers in JavaScript

AmitDiwan
Updated on 19-Apr-2021 07:39:46

451 Views

ProblemWe are required to write a JavaScript function that takes in an array of integers, arr, of even length.Suppose a number num where −num = (arr[0] * arr[0] + arr[1] * arr[1]) * (arr[2] * arr[2] + arr[3] * arr[3]) * … * (arr[n-2] * arr[n-2] + arr[n-1] * arr[n-1])Where n is the length of the array.Our function should find and return an array of two numbers [A, B] such that −A2 + B2 = numFor instance, if the array is −[1, 2, 3, 4]Then num = ( 1 + 4 ) * (9 + 16) = 125Then output should ... Read More

Searching for target string in a strangely sorted array in JavaScript

AmitDiwan
Updated on 19-Apr-2021 07:36:53

177 Views

ProblemWe are required to write a JavaScript function that takes in a word target and an array of sorted(by length(increasing), number of uppercase letters(decreasing), natural order) unique words which always contains the target.The task of our function is to find the index(0 based) of the target in the array of words, which would always be in the list.ExampleFollowing is the code − Live Democonst arr = ['cP', 'rE', 'sZ', 'am', 'bt', 'ev', 'hq', 'rx', 'yi', 'akC', 'nrcVpx', 'iKMVqsj']; const target = 'akC'; const findTarget = (arr = [], target = '') => {    const index = arr.indexOf(target);    return index; ... Read More

Number difference after interchanging their first digits in JavaScript

AmitDiwan
Updated on 19-Apr-2021 07:35:17

103 Views

ProblemWe are required to write a JavaScript function that takes in an array of exactly two numbers. Our function should return the absolute difference between the numbers after interchanging their first digits.For instance, for the array [105, 413], The difference will be: |405 - 113| = 292ExampleFollowing is the code − Live Democonst arr = [105, 413]; const interchangedDigitDiff = (arr = []) => {    arr = arr.map(String);    const [first, second] = arr;    const fChar = first[0];    const sChar = second[0];    const newFirst = sChar + first.substring(1, first.length);    const newSecond = fChar + second.substring(1, second.length); ... Read More

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