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We are required to write a JavaScript function that creates a multi-dimensional array based on some inputs.It should take in three elements, namely −row - the number of subarrays to be present in the array, col - the number of elements in each subarray, val - the val of each element in the subarrays, For example, if the three inputs are 2, 3, 10Then the output should be −const output = [[10, 10, 10], [10, 10, 10]];Therefore, let’s write the code for this function −ExampleThe code for this will be −const row = 2; const col = 3; const val ... Read More
We have a special kind of string that contains characters in couple, like this −const str = "AABBCCDDEE";We are required to construct an object based on this string which should look like this −const obj = { code: "AA", sub: { code: "BB", sub: { code: "CC", sub: { code: "DD", sub: { code: "EE", sub: {} ... Read More
We have to write a function that takes in an array, removes all duplicates from it and inserts the same number of empty strings at the end.For example:If we find 4 duplicate values we have to remove then all and insert four empty strings at the end.Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr = [1, 2, 3, 1, 2, 3, 2, 2, 3, 4, 5, 5, 12, 1, 23, 4, 1]; const deleteAndInsert = arr => { const creds = arr.reduce((acc, val, ind, array) => { let ... Read More
We have to write a simple function in JavaScript that takes in an array of Numbers (nested to any level) and return the greatest number present in the array.For example:If the input array is −const arr = [ 34, 65, 67, [ 43, 76, 87, 23, 56, 7, [ 54, 7, 87, 23, 79, 994, 2 ], 54 ], 54, 4, 2 ];Then the output should be −994We will use recursion to find the greatest number in the array, Therefore, let’s ... Read More
We have an array of numbers and are required to write a function that returns an array with the average of the corresponding element and its predecessor.For the first element, as there are no predecessors, so that very element should be returned.Let’s write the code for this function, we will use the Array.prototype.map() function to solve this problem.ExampleThe code for this will be −const arr = [3, 5, 7, 8, 3, 5, 7, 4, 2, 8, 4, 2, 1]; const consecutiveAverage = arr => { return arr.map((el, ind, array) => { const first = (array[ind-1] || ... Read More
We have to write a function that takes in an array, removes all duplicates from it and inserts the same number of empty strings at the end.For example: If we find 4 duplicate values we have to remove then all and insert four empty strings at the end.Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr = [1, 2, 3, 1, 2, 3, 2, 2, 3, 4, 5, 5, 12, 1, 23, 4, 1]; const deleteAndInsert = arr => { const creds = arr.reduce((acc, val, ind, array) => { ... Read More
We have to write a simple function in JavaScript that takes in an array of Numbers (nested to any level) and return the greatest number present in the array.For example: If the input array is −const arr = [ 34, 65, 67, [ 43, 76, 87, 23, 56, 7, [ 54, 7, 87, 23, 79, 994, 2 ], 54 ], 54, 4, 2 ];Then the output should be −994We will use recursion to find the greatest number in the array.ExampleThe code ... Read More
We are required to write a function that returns the index of the very first element that appears at least twice in the array. If no element appears more than once, we have to return -1. We have to do this in constant space (i.e., without utilizing extra memory).So, let's write the solution for this problem.We will use a for loop to iterate over the array and use the Array.prototype.lastIndexOf() method to check for duplicacy.ExampleThe code for this will be −const arr1 = [0, 1, 1, 2, 3, 4, 4, 5]; const firstRedundant = arr => { for(let i ... Read More
We are supposed to write a function that takes in an array of number/string literals. The function should remove all the redundant consecutive elements of the array without using extra memory space.For example, if the input array is −const arr = [17, 17, 17, 12, 12, 354, 354, 1, 1, 1];Then the output should be −const output = [17, 12, 354, 1];Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr = [17, 17, 17, 12, 12, 354, 354, 1, 1, 1]; const comp = (arr, len = 0, deletable = false) => { ... Read More
We have an array of numbers that have got identical entries. We are required to write a function that takes in the array and groups all the identical entries into one subarray and returns the new array thus formed.For example: If the input array is −const arr = [234, 65, 65, 2, 2, 234];// then the output should be −const output = [[234, 234], [65, 65], [2, 2]];We will use a Hashmap to keep a track of the elements already occurred and iterate over the array using a for loop.Therefore, let’s write the code for this function −ExampleThe code for ... Read More