In Mathematics, a Mersenne prime is a number that can be written in the form M(n) = 2^n − 1 for some integer n and is actually a prime number.For example − The first four Mersenne primes are 3, 7, 31, and 127We are required to write a JavaScript function that takes in a number and checks whether it is a Mersenne prime or not. Let’s write the code for this functionExampleconst isPrime = num => {    let i = 2;    while(i {    if(!isPrime(num)){       return false;    };    let i = 0, ... Read More

We are required to write a JavaScript function that takes in two strings and checks whether first string starts with second or notFor example −If the two strings are: “Disaster management report” “Disas” Then our function should return trueLet's write the code for this function −Exampleconst first = 'The game is on'; const second = 'The'; const startsWith = (first, second) => {    const { length } = second;    const { length: l } = first;    const sub = first.substr(0, length);    return sub === second; }; console.log(startsWith(first, second));OutputThe output in the console will be −true

An element in an array of Numbers is a leader if it is greater than all the elements on its right side. We are required to write a JavaScript function that takes in an array of Numbers and returns a subarray of all the elements that are fulfil the criteria of being a leader element.For example −If the input array is: [23, 55, 2, 56, 3, 6, 7, 1] Then the output should be: [56, 7, 1]Let's write the code for this function −Exampleconst arr = [23, 55, 2, 56, 3, 6, 7, 1]; const leaderArray = arr => { ... Read More

We are required to write a JavaScript function that takes in an array of numbers with repetitive values and returns the number that appears for more than (n/2) number of times where n is the length of the array. If there is no such element in the array, our function should return falseLet's write the code for this function −Exampleconst arr = [12, 5, 67, 12, 4, 12, 4, 12, 6, 12, 12]; const arr1 = [3, 565, 7, 23, 87, 23, 3, 65, 1, 3, 6, 7]; const findMajority = arr => {    let maxChar = -Infinity, maxCount ... Read More

We are required to write a JavaScript function that takes in two arrays of Numbers, say first and second and checks for their equality.Equality in our case will be determined by one of these two conditions −The arrays are equal if they contain the same elements irrespective of their order.If the sum of all the elements of the first array and second array is equal.For example −[3, 5, 6, 7, 7] and [7, 5, 3, 7, 6] are equal arrays [1, 2, 3, 1, 2] and [7, 2] are also equal arrays but [3, 4, 2, 5] and [2, 3, ... Read More

We are required to write a JavaScript function that takes in two strings, say, string1 and string2 and determines whether the string1 ends with string2 or not.For example −"The game is on" Here, "on" should return trueWhile, "the game is off" Above, “of" should return falseLet's write the code for this function −Exampleconst first = 'The game is on'; const second = ' on'; const endsWith = (first, second) => {    const { length } = second;    const { length: l } = first;    const sub = first.substr(l - length, length);    return sub === second; }; ... Read More

In the decimal number system, ugly numbers are those positive integers whose only prime factors are 2, 3 or 5.For example − Integers from 1 to 10 are all ugly numbers, 12 is an ugly number as well.Our job is to write a JavaScript function that takes in a Number and determines whether it is an ugly number or not.Let's write the code for this function −Exampleconst num = 274; const isUgly = num => {    while(num !== 1){       if(num % 2 === 0){          num /= 2;       } else ... Read More

We are required to write a JavaScript function that takes in a string and returns a new string with all non-duplicate characters removed from it.For example −If the input string is −"teeth_foot"Then the output should be −"teetoot"Therefore, let's write the code for this function −Exampleconst str = 'teeth_foot'; const removeNonDuplicate = str => {    const strArray = str.split("");    const duplicateArray = strArray.filter(el => {       return strArray.indexOf(el) !== strArray.lastIndexOf(el);    });    return duplicateArray.join(""); }; console.log(removeNonDuplicate(str));OutputThe output in the console will be −teetoot

We are required to write a JavaScript function that takes in a string and returns a new string which has all the words reversed from the original string.For example −If the original string is −"Hello World how is it outside"Then the output should be −"olleH dlroW woH si ti edistuo"Now, let's write the code for this function −Exampleconst str = 'Hello World how is it outside'; const reverseSentence = str => {    const arr = str.split(" ");    const reversed = arr.map(el => {       return el.split('').reverse().join("");    });    return reversed.join(" "); }; console.log(reverseSentence(str));OutputThe output in ... Read More

Let’s say, we have two strings that contains characters in no specific order. We are required to write a function that takes in these two strings and returns a modified version of the second string in which all the characters that were present in the first string are omitted.Following are our strings −const first = "hello world"; const second = "hey there";Following is our function to remove all characters of first string from second −const removeAll = (first, second) => {    const newArr = second.split("").filter(el => {       return !first.includes(el);    });    return newArr.join(""); };Let's write ... Read More