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Found 9150 Articles for Object Oriented Programming

461 Views
Suppose we have an object like this −const obj = { key1: 56, key2: 67, key3: 23, key4: 11, key5: 88 };We are required to write a JavaScript function that takes in this object and returns a sorted array like this −const arr = [11, 23, 56, 67, 88];Here, we sorted the object values and placed them in an array.ExampleFollowing is the code −const obj = { key1: 56, key2: 67, key3: 23, key4: 11, key5: 88 }; const sortObject = obj => { const arr = Object.keys(obj).map(el => { return obj[el]; }); arr.sort((a, b) => { return a - b; }); return arr; }; console.log(sortObject(obj));OutputThis will produce the following output in console −[ 11, 23, 56, 67, 88 ]

330 Views
Suppose, we have an array of objects like this −const arr = [ {id: 1, name: "Mohan"}, {id: 2, name: "Sohan"}, {id: 3, name: "Rohan"} ];We are required to write a function that takes one such array and constructs an object from it with the id property as key and name as valueThe output for the above array should be −const output = {1:{name:"Mohan"}, 2:{name:"Sohan"}, 3:{name:"Rohan"}}ExampleFollowing is the code −const arr = [ {id: 1, name: "Mohan"}, {id: 2, name: "Sohan"}, {id: 3, name: "Rohan"} ]; const arrayToObject = arr => { const ... Read More

127 Views
Suppose, we have an array of objects like this −const arr = [ {'ID-01':1}, {'ID-02':3}, {'ID-01':3}, {'ID-02':5} ];We are required to add the values for all these objects together that have identical keysTherefore, for this array, the output should be −const output = [{'ID-01':4}, {'ID-02':8}];We will loop over the array, check for existing objects with the same keys, if they are there, we add value to it otherwise we push new objects to the array.ExampleFollowing is the code −const arr = [ {'ID-01':1}, {'ID-02':3}, {'ID-01':3}, {'ID-02':5} ]; const indexOf = function(key){ ... Read More

315 Views
Suppose we have an array like this −const arr = [ {unit: 35, brand: 'CENTURY'}, {unit: 35, brand: 'BADGER'}, {unit: 25, brand: 'CENTURY'}, {unit: 15, brand: 'CENTURY'}, {unit: 25, brand: 'XEGAR'} ];We are required to write a function that groups all the brand properties of objects whose unit property is the same.Like for the above array, the new array should be −const output = [ {unit: 35, brand: 'CENTURY, BADGER'}, {unit: 25, brand: 'CENTURY, XEGAR'}, {unit: 15, brand: 'CENTURY'} ];We will loop over the array, search for the object with unit value ... Read More

968 Views
We are required to write a JavaScript function that takes in an array of String / Number literals and returns a subarray of all the elements that were palindrome in the original array.For example −If the input array is −const arr = ['carecar', 1344, 12321, 'did', 'cannot'];Then the output should be −const output = [12321, 'did'];We will create a helper function that takes in a number or a string and checks if it’s a boolean or not. Then we will loop over the array, filter the palindrome elements and return the filtered arrayExampleFollowing is the code −const arr = ['carecar', ... Read More

190 Views
Suppose, we have an object like this −const products = { "Pineapple":38, "Apple":110, "Pear":109 };All the keys are unique in themselves and all the values are unique in themselves. We are required to write a function that accepts a value and returns its keyFor example: findKey(110) should return −"Apple"We will approach this problem by first reverse mapping the values to keys and then simply using object notations to find their values.ExampleFollowing is the code −const products = { "Pineapple":38, "Apple":110, "Pear":109 }; const findKey = (obj, val) => { const res = {}; ... Read More

597 Views
We are required to write a JavaScript function that takes in a string and any number of characters specified as separators. Our function should return a splitted array of the string based on all the separators specified.For example −If the string is −const str = 'rttt.trt/trfd/trtr, tr';And the separators are −const sep = ['/', '.', ', '];Then the output should be −const output = [ 'rttt', 'trt', 'trfd', 'trtr' ];ExampleFollowing is the code −const str = 'rttt.trt/trfd/trtr, tr'; const splitMultiple = (str, ...separator) => { const res = []; let start = 0; for(let i = 0; ... Read More

1K+ Views
We are required to write a function that, given a number, say, 123, will output an array −[100,20,3]Basically, the function is expected to return an array that contains the place value of all the digits present in the number taken as an argument by the function.We can solve this problem by using a recursive approach.ExampleFollowing is the code −const num = 123; const placeValue = (num, res = [], factor = 1) => { if(num){ const val = (num % 10) * factor; res.unshift(val); return placeValue(Math.floor(num / 10), res, factor * 10); }; return res; }; console.log(placeValue(num));OutputThis will produce the following output in console −[ 100, 20, 3 ]

351 Views
Suppose we have an array of arrays of numbers like this −const arr = [[1, 45], [1, 34], [1, 49], [2, 34], [4, 78], [2, 67], [4, 65]];Each subarray is bound to contain strictly two elements. We are required to write a function that constructs a new array where all second elements of the subarrays that have similar first value are grouped together.Therefore, for the array above, the output should look like −const output = [ [45, 34, 49], [34, 67], [78, 65] ];We can make use of the Array.prototype.reduce() method that takes help of a Map() ... Read More

701 Views
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 subarrayval minus; the val of each element in the subarraysFor example, if the three inputs are 2, 3, 10Then the output should be −const output = [[10, 10, 10], [10, 10, 10]];ExampleFollowing is the code −const row = 2; const col = 3; const val = 10; const constructArray = (row, col, val) => { ... Read More