We are required to write a JavaScript function that takes in a string and returns the index of the first character that appears twice in the string. If there is no such character then we should return -1.Let’s say the following is our string −const str = 'Hello world, how are you';We need to find the index of the first repeating character.ExampleThe code for this will be −const str = 'Hello world, how are you'; const firstRepeating = str => {    const map = new Map();    for(let i = 0; i < str.length; i++){       if(map.has(str[i])){ ... Read More

We are required to write a JavaScript function that takes in two strings and find the number of corresponding dissimilarities in the strings. The corresponding elements will be dissimilar if they are not equalExampleLet’s say the following are our strings −const str1 = 'Hello world!!!'; const str2 = 'Hellp world111';ExampleThe code for this will be −const str1 = 'Hello world!!!'; const str2 = 'Hellp world111'; const dissimilarity = (str1 = '', str2 = '') => {    let count = 0;    for(let i = 0; i < str1.length; i++){       if(str1[i] === str2[i]){         ... Read More

We are required to write a JavaScript function that takes in a string and reverses the words in the string that have an even number of characters in them.Let’s say the following is our string −const str = 'This is an example string';We want to reverse the even length words of the above string i.e. reverse the following words −This is an stringExampleThe code for this will be −const str = 'This is an example string'; const isEven = str => !(str.length % 2); const reverseEvenWords = (str = '') => {    const strArr = str.split(' ');    return ... Read More

We have to write a function that takes in an array and returns the index of the first nonconsecutive number from it.Like all the numbers will be in an arithmetic progression of common difference 1. But the number, which violates this rule, we have to return its index. If all the numbers are in perfect order, we should return -1.ExampleLet’s write the code for this function −const arr = [1, 2, 3, 4, 5, 6, 8, 9, 10]; const secondArr = [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]; const findException = (arr) => { ... Read More

We are required to write a function that takes in a string as the first and the only argument and constructs an object with its keys based on the unique characters of the string and value of each key being defaulted to 0.For example: If the input string is −const str = 'hello world!';OutputThen the output object should be −const obj = { "h": 0, "e": 0, "l": 0, "o": 0, " ": 0, "w": 0, "r": 0, "d": 0, "!": 0 };ExampleLet’s write the code for this function −const str = 'hello world!'; const stringToObject = str => { ... Read More

We are required to write a function, let’s say splitNumber() that takes in a positive integer and returns an array populated with the place values of all the digits of the number.For example −If the input number is −const num = 1234;OutputThen the output should be −const output = [1000, 200, 30, 4];Let’s write the code for this function.This problem is very suitable for a recursive approach as we will be iterating over each digit of the number.Therefore, the recursive function that returns an array of respective place values of digits will be given by −Exampleconst splitNumber = (num, arr ... Read More

We are required to write a JavaScript function that takes in a number and returns a number that can be represented as a power of 2 which is nearest to the input number.For example: If the input number if 145.Then the output should be 128 because 145 is the nearest such number to 128 which can be represented as 2^n for some whole number value of n.ExampleThe code for this will be −const num = 145; const nearestPowerOfTwo = num => {    // dealing only with non negative numbers    if(num < 0){       num *= -1; ... Read More

We are required to write a JavaScript function that takes in a sorted array of literals as the first argument and a query literal as second. Then our function should make use of the Binary Search algorithm to find whether the query exists in the array or not.If it exists, we return its index in the array, otherwise we return -1.ExampleThe code for this will be −const arr = [1, 2, 3, 5, 6, 7, 10, 11, 14, 15, 17, 19, 20, 22, 23]; const binarySearch = (arr, query) => {    let index = Math.floor(arr.length / 2);    if ... Read More

We are required to write a JavaScript function that takes in three numbers (representing the coefficient of quadratic term, coefficient of linear term and the constant respectively in a quadratic quadratic).And we are required to find the roots, (if they are real roots) otherwise we have to return false.ExampleThe code for this will be −const coeff = [1, 12, 3]; const findRoots = co => {    const [a, b, c] = co;    const discriminant = (b * b) - 4 * a * c;    // non real roots    if(discriminant < 0){       return false; ... Read More

If we unique values in a vector in R and they are repeated then we can find the frequency of those unique values, this will help us to understand the distribution of the values in the vector. On the basis of that distribution analysis, we can proceed with the further analysis that could be used. This can be done with the help of rle function.Example Live Demox1