Javascript Articles - Page 206 of 607

We are required to write a JavaScript function that takes in a string as the only argument.The string might contain both uppercase and lowercase alphabets.The function should construct a new string based on the input string in which all the uppercase letters are converted to lowercase and all the lowercase letters are converted to uppercase.ExampleFollowing is the code −const str = 'ThIs Is A STriNG'; const findLetter = (char = '') => {    if(char.toLowerCase() === char.toUpperCase){       return char;    }else if(char.toLowerCase() === char){       return char.toUpperCase();    }else{       return char.toLowerCase();   ... Read More

It is a common practice that when websites display anyone's private email address they often mask it in order to maintain privacy.Therefore for example −If someone's email address is −const email = 'ramkumar@example.com';Then it is displayed like this −const masked = 'r...r@example.com';We are required to write a JavaScript function that takes in an email string and returns the masked email for that string.ExampleFollowing is the code −const email = 'ramkumar@example.com'; const maskEmail = (email = '') => {    const [name, domain] = email.split('@');    const { length: len } = name;    const maskedName = name[0] + '...' + ... Read More

The partition of a positive integer n is a way of writing n as a sum of positive integers. Two sums that differ only in the order of their summands are considered the same partition.For example, 4 can be partitioned in five distinct ways −4 3 + 1 2 + 2 2 + 1 + 1 1 + 1 + 1 + 1We are required to write a JavaScript function that takes in a positive integer as the only argument. The function should find and return all the possible ways of partitioning that integer.ExampleFollowing is the code −const findPartitions = (num = 1) => {    const arr = Array(num + 1).fill(null).map(() => {       return Array(num + 1).fill(null);    });    for (let j = 1; j

We are required to write a JavaScript function that takes in a positive integer as the only argument. The function should find and return the square root of the number provided as the input.ExampleFollowing is the code −const squareRoot = (num, precision = 0) => {    if (num deviation) {       res -= ((res ** 2) - num) / (2 * res);    };    return Math.round(res * (10 ** precision)) / (10 ** precision); }; console.log(squareRoot(16)); console.log(squareRoot(161, 3)); console.log(squareRoot(1611, 4));OutputFollowing is the output on console −4 12.689 40.1373

We are required to write a JavaScript function that takes in two arrays of literals, let’s call them arr1 and arr2.The function should find the longest common streak of literals in the arrays. The function should finally return an array of those literals.For example −If the input arrays are −const arr1 = ['a', 'b', 'c', 'd', 'e']; const arr2 = ['k', 'j', 'b', 'c', 'd', 'w'];Then the output array should be −const output = ['b', 'c', 'd'];ExampleFollowing is the code −const arr1 = ['a', 'b', 'c', 'd', 'e']; const arr2 = ['k', 'j', 'b', 'c', 'd', 'w']; const longestCommonSubsequence = ... Read More

We are required to write a JavaScript function that takes in an array of array of positive and negative integers. Since the array also contains negative elements, the sum of contiguous elements can possibly be negative or positive.Our function should pick an array of contiguous elements from the array that sums the greatest. Finally, the function should return that array.For example −If the input array is −const arr = [-2, -3, 4, -1, -2, 1, 5, -3];Then the maximum possible sum is 7 and the output subarray should be −const output = [4, -1, -2, 1, 5];ExampleFollowing is the code ... Read More

We are required to write a JavaScript function that takes in two strings. Let’s call them str1 and str2. The function should then find out the longest consecutive string that is common to both the input strings and return that common string.For example −If the input strings are −const str1 = 'ABABC'; const str2 = 'BABCA';Then the output string should be −const output = 'BABC';ExampleFollowing is the code −const str1 = 'ABABC'; const str2 = 'BABCA'; const findCommon = (str1 = '', str2 = '') => {    const s1 = [...str1];    const s2 = [...str2];    const arr ... Read More

Caesar Cipher AlgorithmThe Caesar Cipher algorithm is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet.For exampleWith a left shift of 3, D would be replaced by A, E would become B, and so on. We are required to write a JavaScript function that takes in a string to be encrypted as the first argument and a shift amount as the second argument.The shift amount can be a positive or negative integer ... Read More

Suppose we have an array of m * n order. A person starts at the start block of the 2-D array (0, 0) and he wants to reach the end (m, n). The limitation is that at once, he can either move one step down or one step right.We are required to write a JavaScript function that takes in the height and width of the 2-D grid.The function should find out the number of unique paths that are available to the person to reach to the end.ExampleFollowing is the code −const height = 3; const width = 4; const findUniquePath ... Read More

We are required to write a JavaScript function that takes in an array of arrays of n * n order (square matrix). The function should rotate the array by 90 degrees (clockwise). The condition is that we have to do this in place (without allocating any extra array).For example −If the input array is −const arr = [    [1, 2, 3],    [4, 5, 6],    [7, 8, 9] ];Then the rotated array should look like −const output = [    [7, 4, 1],    [8, 5, 2],    [9, 6, 3], ];ExampleFollowing is the code −const arr = ... Read More