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Articles by AmitDiwan
Page 324 of 840
JavaScript Count the number of unique elements in an array of objects by an object property
In JavaScript, when dealing with arrays of objects, it's common to need to extract specific values based on object properties and count how many unique occurrences exist for a particular property. Whether you're processing a list of users, products, or any other data structure, counting unique elements by a property is a useful operation. In this article, we'll discuss how to count the number of unique elements in an array of objects based on a specific property using a few different techniques. Problem Statement You have an array of objects representing users, each with properties like name, ...
Read MoreHow to call a function repeatedly every 5 seconds in JavaScript?
In JavaScript, setInterval() allows you to execute a function repeatedly at specified time intervals. To call a function every 5 seconds, you pass the function and 5000 milliseconds as arguments. Syntax setInterval(function, delay); Where function is the function to execute and delay is the time in milliseconds between executions. Basic Example function myFunction() { console.log("Function called at:", new Date().toLocaleTimeString()); } // Call myFunction every 5 seconds (5000 milliseconds) setInterval(myFunction, 5000); Function called at: 2:30:15 PM Function called at: 2:30:20 PM Function called at: 2:30:25 ...
Read MorePushing positives and negatives to separate arrays in JavaScript
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. Using Array.reduce() Method The 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) => { ...
Read MoreGrade book challenge JavaScript
We are required to write a function that finds the mean of the three scores passed to it and returns the letter value associated with that grade according to the following table. Grade Scale Score Range Grade 90-100 A 80-89 B ...
Read MoreFinding the k-prime numbers with a specific distance in a range in JavaScript
K-Prime Numbers A natural number is called k-prime if it has exactly k prime factors, counted with multiplicity. For example, 4 is a 2-prime number because 4 = 2 × 2, and both instances of 2 are counted separately. Similarly, 8 is a 3-prime number because 8 = 2 × 2 × 2, giving us three prime factors. Problem We need to write a JavaScript function that takes a number k, a distance, and a range. The function should return an array of pairs containing k-prime numbers within the range where the distance between them equals ...
Read MoreSorting only a part of an array JavaScript
We are required to write a JavaScript function that takes in an array of strings as the first argument and two numbers as second and third argument respectively. The purpose of our function is to sort the array. But we have to sort only that part of the array that falls between the start and end indices specified by second and third argument. Keeping all the other elements unchanged. For example: const arr = ['z', 'b', 'a']; sortBetween(arr, 0, 1); This function should sort the elements at 0 and 1 index only. And the ...
Read MoreConverting decimal to binary or hex based on a condition in JavaScript
Problem We need to write a JavaScript function that takes in a number n and converts it based on a condition: If a number is even, convert it to binary. If a number is odd, convert it to hex. Solution We can use JavaScript's toString() method with different radix values to perform the conversion. For binary conversion, we use radix 2, and for hexadecimal conversion, we use radix 16. Example Here's the implementation: const num = 1457; const conditionalConvert = (num = 1) ...
Read MoreFinding score of brackets in JavaScript
We are required to write a JavaScript function that takes in a balanced square bracket string as an argument and computes its score based on specific rules. Scoring Rules The bracket scoring follows these rules: [] has score 1 AB has score A + B, where A and B are balanced bracket strings [A] has score 2 * A, where A is a balanced bracket string Example Input and Output For the input string '[][]': Input: '[][]' Output: 2 This works because [] scores 1, and [][] is two ...
Read MoreHow to call a function that returns another function in JavaScript?
In JavaScript, calling a function that returns another function involves understanding higher-order functions and closures. When a function returns another function, you can either store the returned function in a variable or call it immediately using double parentheses. Basic Syntax There are two main ways to call a function that returns another function: // Method 1: Store in variable then call let returnedFunction = outerFunction(); returnedFunction(); // Method 2: Call immediately outerFunction()(); Simple Example let outerFunction = function() { ...
Read MoreHow to transform two or more spaces in a string in only one space? JavaScript
In JavaScript, you can transform multiple consecutive spaces in a string into a single space using regular expressions with the replace() method. This is useful for cleaning up text input or formatting strings consistently. The Regular Expression Approach The most effective method uses the regular expression /\s{2, }/g where: \s matches any whitespace character (spaces, tabs, newlines) {2, } matches two or more consecutive occurrences g is the global flag to replace all instances Method 1: Using replace() with Regular Expression ...
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