Javascript Articles - Page 278 of 534

We are required to write a JavaScript function that contains the following string −const str = 'This string will be used to calculate frequency distribution';We need to return an object that represents the frequency distribution of various elements present in the array.ExampleFollowing is the code −const str = 'This string will be used to calculate frequency distribution'; const frequencyDistribution = str => {    const map = {};    for(let i = 0; i < str.length; i++){       map[str[i]] = (map[str[i]] || 0) + 1;    };    return map; }; console.log(frequencyDistribution(str));OutputFollowing is the output in the console ... Read More

We are required to write a JavaScript function that takes in two strings. The first string is some mistyped string and the second string is the correct version of this sting. We can assume that the two strings we are getting as argument will always have the same length.We have to return the number of mistakes that exist in the first array.ExampleFollowing is the code −const str1 = 'Tkos am er exakgrg fetwnh'; const str2 = 'This is an example string'; const countMistakes = (mistaken, correct) => {    let count = 0;    for(let i = 0; i < ... Read More

We are required to write a JavaScript function that takes in two arrays of numbers, second being smaller in size than the first.Our function should be a sorted version of the first array (say in increasing order) but put all the elements that are common in both arrays to the front.For example − If the two arrays are −const arr1 = [5, 4, 3, 2, 1]; const arr2 = [2, 3];Then the output should be −const output = [2, 3, 1, 4, 5];ExampleFollowing is the code −const arr1 = [5, 4, 3, 2, 1]; const arr2 = [2, 3]; // ... Read More

Proper FractionA proper fraction is the one that exists in the p/q form (both p and q being natural numbers)Mixed FractionSuppose we divide the numerator of a fraction (say a) with its denominator (say b), to get quotient q and remainder r.The mixed fraction form for fraction (a/b) will be −qrbAnd it is pronounced as "q wholes and r by b”.We are required to write a JavaScript function that takes in an array of exactly two numbers representing a proper fraction and our function should return an array with three numbers representing its mixed formExampleFollowing is the code −const arr ... Read More

We are required to write a JavaScript function that takes in a string that contains strings joined by whitespaces. Our function should create a new string that has all the words from the original string and the words whose length is a prime number reversed i.e. words with length 2, 3, 5, 7, 100, etc.ExampleFollowing is the code −const str = 'His father is an engineer by profession'; // helper functions const isPrime = n => {    if (n===1){       return false;    }else if(n === 2){       return true;    }else{       ... Read More

We are required to write a JavaScript function that takes in two strings, creates and returns a new string with first two words of first string, next two words of second string, then first, then second and so on.For example −If the strings are −const str1 = 'Hello world'; const str2 = 'How are you btw';Then the output should be −const output = 'HeHollw o arwoe rlyodu btw';ExampleLet us write the code for this function −const str1 = 'Hello world'; const str2 = 'How are you btw'; const twiceJoin = (str1 = '', str2 = '') => {    let ... Read More

We are required to write a JavaScript function that takes in a string and returns the character which makes second most appearances in the string.ExampleFollowing is the code −const str = 'Hello world, I have never seen such a beautiful weather in the world'; const secondFrequent = str => {    const map = {};    for(let i = 0; i < str.length; i++){       map[str[i]] = (map[str[i]] || 0) + 1;    };    const freqArr = Object.keys(map).map(el => [el, map[el]]);    freqArr.sort((a, b) => b[1] - a[1]);    return freqArr[1][0]; }; console.log(secondFrequent(str));OutputFollowing is the output in the console −e

We are required to write a JavaScript function that takes in a string and starts mapping its characters from 0. And every time the function encounters a unique (non-duplicate) character, it should increase the mapping count by 1 otherwise map the same number for duplicate characters.For example − If the string is −const str = 'heeeyyyy';Then the output should be −const output = [0, 1, 1, 1, 2, 2, 2, 2];ExampleFollowing is the code −const str = 'heeeyyyy'; const mapString = str => {    const res = [];    let curr = '', count = -1;    for(let i ... Read More

We are required to write a JavaScript function that takes in a number and the function establishes if the provided number is a semiprime or not.SemiprimeA semiprime number is that number which is a special type of composite number that is a product of two prime numbers. For example: 6, 15, 10, 77 are all semiprime. The square of a prime number is also semiprime, like 4, 9, 25 etc.ExampleFollowing is the code to check semi-prime numbers −const num = 141; const checkSemiprime = num => {    let cnt = 0;    for (let i = 2; cnt < ... Read More

We are required to write a JavaScript function that takes in an array of numbers and reorders the digit of all the numbers internally in a specific order (lets say in ascending order for the sake of this problem).For example − If the array is −const arr = [543, 65, 343, 75, 567, 878, 87];Then the output should be −const output = [345, 56, 334, 57, 567, 788, 78];ExampleFollowing is the code −const arr = [543, 65, 343, 75, 567, 878, 87]; const ascendNumber = num => {    const numArr = String(num).split('').map(el => +el);    numArr.sort((a, b) => a ... Read More