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We are required to write a JavaScript function that takes in two strings. Let’s call them str1 and str2.Our function should check either str1 starts with str2 or it ends with str2. If this is the case, we should return true otherwise we should return false.ExampleFollowing is the code −const str = 'this is an example string'; const startsOrEndsWith = (str1 = '', str2 = '') => { if(str2.length > str1.length){ return false; }; if(str1 === str2){ return true; }; const { length: l1 } = str1; const ... Read More
We are required to write a JavaScript function that takes in an array of Numbers as the only argument. The function should calculate and return the sum of alternative elements of the array.For example −If the input array is −const arr = [1, 2, 3, 4, 5, 6, 7];Then the output should be −1 + 3 + 5 + 7 = 16ExampleFollowing is the code −const arr = [1, 2, 3, 4, 5, 6, 7]; const alternativeSum = (arr = []) => { let sum = 0; for(let i = 0; i < arr.length; i++){ const el = arr[i]; if(i % 2 !== 0){ continue; }; sum += el; }; return sum; }; console.log(alternativeSum(arr));OutputFollowing is the output on console −16
The delete operator in JavaScript is actually an object operator (used with objects).But since arrays are also indexed objects in JavaScript, we can use the delete operator with arrays as well.Consider the following array of literals −const arr = ['a', 'b', 'c', 'd', 'e'];ExampleLet us now execute the following program and guess the expected output −const arr = ['a', 'b', 'c', 'd', 'e']; delete arr[4]; console.log(arr); console.log(arr.length);OutputThe output of this program in the console will be −[ 'a', 'b', 'c', 'd', ] 5Understanding the output −Since we deleted one index value of the array, we expected the array.length to ... Read More
We are required to write a JavaScript function that takes in a number as the first and the only argument. The function should use recursion to construct a string representing the binary notation of that number.For example −f(4) = '100' f(1000) = '1111101000' f(8) = '1000'ExampleFollowing is the code −const decimalToBinary = (num) => { if(num >= 1) { // If num is not divisible by 2 then recursively return proceeding // binary of the num minus 1, 1 is added for the leftover 1 num if (num % 2) ... Read More
We are required to write a JavaScript function that takes in a string as the only argument.The function should reverse the order of the words in the string and return the new string.The only condition is that we cannot use the inbuilt array method reverse().For example −If the input string is −const str = 'this is a string';Then the output string should be −const str = 'this is a string';ExampleFollowing is the code −const str = 'this is a string'; const reverseWordOrder = (str = '') => { const strArr = str.split(' '); let temp = ''; ... Read More
We are required to write a JavaScript function that takes in two arrays of numbers, let’s say arr1 and arr2. The function should find the intersection between the elements of the array. i.e., the elements that appear in both the arrays.The only condition is that if we encountered one element before as intersected, we should not consider it again even if appears again in both the arrays.For example −If the input arrays are −const arr1 = [1, 5, 7, 3, 1]; const arr2 = [1, 7, 3, 1, 6];Then the output array should be −const output = [1, 3, 7];However, ... Read More
We are required to write a JavaScript function that takes in an array of Numbers. The function should construct a new array based on the original array. Each corresponding element of the new array should be the product of all the elements of the original array including that element.For example −If the input array is −const arr = [1, 2, 3, 4, 5];Then the output array should be −const output = [120, 60, 40, 30, 24];We have to achieve this in linear time and constant space (obviously excluding the space used up in constructing the new array).ExampleFollowing is the code ... Read More
We are required to write a JavaScript function that takes in an array of Numbers as the first argument and a single number as the second argument.The function should find and return that number from the array which is closest to the number specified by the second argument.For example −const arr = [34, 67, 31, 53, 89, 12, 4]; const num = 41;Then the output should be 34.ExampleFollowing is the code −const arr = [34, 67, 31, 53, 89, 12, 4]; const num = 41; const findClosest = (arr = [], num) => { let curr = arr[0]; ... Read More
In this problem, we are given an array arr[] and a number M. Our task is to create a program to calculate the Maximum Weight Difference in C++.Problem descriptionWe will find M elements from the array such that the absolute difference between the sum and the sum of the rest elements is maximum.Let’s take an example to understand the problem, Inputarr[] = {3, 1, 6, 9, 4} M = 3Output15ExplanationWe will consider 4, 6, 9. The sum is 19. The absolute difference with the sum of rest numbers is|19 − 4| = 15Solution ApproachA simple solution to the problem is ... Read More
In this problem, we are given an array arr[] of size n consisting of positive values. Our task is to create a program to find the maximum subsequence sum in such a way that no two consecutive elements of the array.Problem Description − We need to find the sum of subarray which has elements of the array but no two adjacent elements of the array can be taken into consideration.ExampleLet’s take an example to understand the problem, Inputarr[] = {5, 2, 1, 9, 6}OutputExplanation −Subarray sum are : {5, 1, 6}, sum = 5 + 1 + 6 = 12 ... Read More