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We are required to write a function that takes in an array and returns an object with two arrays positive and negative. They both should be containing all positive and negative items respectively from the array.We will be using the Array.prototype.reduce() method to pick desired elements and put them into an object of two arrays.ExampleThe code for this will be −const arr = [97, -108, 13, -12, 133, -887, 32, -15, 33, -77]; const splitArray = (arr) => { return arr.reduce((acc, val) => { if(val < 0){ acc['negative'].push(val); }else{ ... Read More
Suppose we have an array of objects containing some years and weeks data like this −const arr = [ {year: 2017, week: 45}, {year: 2017, week: 46}, {year: 2017, week: 47}, {year: 2017, week: 48}, {year: 2017, week: 50}, {year: 2017, week: 52}, {year: 2018, week: 1}, {year: 2018, week: 2}, {year: 2018, week: 5} ];We are required to write a JavaScript function that takes in one such array. The function should return a new array where all the objects that have common value for the "year" property are grouped into ... Read More
We are required to write a JavaScript function that takes in an array of numbers representing ages of some people.Then the function should bring all the ages less than 18 to the front of the array without using any extra memory.ExampleThe code for this will be −const ages = [23, 56, 56, 3, 67, 8, 4, 34, 23, 12, 67, 16, 47]; const sorter = (a, b) => { if (a < 18) { return -1; }; if (b < 18) { return 1; }; return 0; } const sortByAdults = arr => { arr.sort(sorter); }; sortByAdults(ages); console.log(ages);OutputThe output in the console −[ 16, 12, 4, 8, 3, 23, 56, 56, 67, 34, 23, 67, 47 ]
Suppose we have a two-dimensional array of numbers like this −const arr = [ [1, 3, 2], [5, 2, 1, 4], [2, 1] ];We are required to write a JavaScript function that groups all the identical numbers into their own separate subarray, and then the function should sort the group array to place the subarrays into increasing order.Therefore, finally the new array should look like −const output = [ [1, 1, 1], [2, 2, 2], [4], [3], [5] ];ExampleThe code for this will be −const arr = [ [1, 3, 2], ... Read More
We are required to write a JavaScript function that takes in a string as the first argument and an array of numbers. Our function should replace all the characters in the string at indices that are specified by the array elements taken as the second argument with an asterisk.ExampleThe code for this will be −const str = "Lorem ipsum dolor sit amet consectetur adipiscing elit"; const arr = [4, 7, 9, 12, 15]; const replceWithAsterisk = (str, indices) => { let res = ''; res = indices.reduce((acc, val) => { acc[val] = '*'; ... Read More
Suppose, we array of arrays like this −const arr = [ [-73.9280684530257, 40.8099975343718], [-73.9282820374729, 40.8100875554645], [-73.9280124002104, 40.8103130893677], [-73.927875543761, 40.8102554080229], [-73.9280684530257, 40.8099975343718] ];Here each subarray represents a point on a 2-D plane, and each point is a vertex of n sided polygon where n is the number of subarrays in the input arrays.We are required to write a JavaScript function that takes in one such array and returns a new array of n subarrays, each representing the midpoint of corresponding sides of the polygon.ExampleThe code for this will be −const arr = [ [-73.9280684530257, 40.8099975343718], [-73.9282820374729, 40.8100875554645], [-73.9280124002104, 40.8103130893677], [-73.927875543761, 40.8102554080229], [-73.9280684530257, 40.8099975343718] ]; const findCenters = arr => { const centerArray = []; for(i = 0; i
Suppose we have two arrays, the first array contains the scheduled date for some events and the second array contains the names of those events, like this −const dates = [ { id:"1", date:"2017-11-07" }, { id:"1", date:"2017-11-08" }, { id:"2", date:"2017-11-07" }, { id:"2", date:"2017-11-08" } ]; const names = [ { id:"1", name:"Pervies, Peter" }, { ... Read More
Suppose we have an array of arrays like this −const arr = [ [ "Serta", "Black Friday" ], [ "Serta", "Black Friday" ], [ "Simmons", "Black Friday" ], [ "Simmons", "Black Friday" ], [ "Simmons", "Black Friday" ], [ "Simmons", "Black Friday" ] ];We are required to write a JavaScript function that ... Read More
Suppose we have two arrays of literals like these −const arr1 = [1, 3, 2, 4, 5, 6]; const arr2 = [1, 2, 5];We are required to write a JavaScript function that takes in two such arrays. Then our function should return a new array that contains all the elements of arr1 but sorted according to arr2.Like the elements that appear in both the array should appear first according to their order in the second array followed by the elements only present in first array retaining their order.ExampleThe code for this will be −const arr1 = [1, 3, 2, 4, ... Read More