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Suppose we have an array of objects like this − const arr = [ {userId: "3t5bsFB4PJmA3oTnm", from: 1, to: 6}, {userId: "3t5bsFB4PJmA3oTnm", from: 7, to: 15}, {userId: "3t5bsFB4PJmA3oTnm", from: 172, to: 181}, {userId: "3t5bsFB4PJmA3oTnm", from: 182, to: 190} ]; We need to write a JavaScript function that groups consecutive objects based on their "from" and "to" properties. Objects are considered consecutive when the "to" value of one object plus 1 equals the "from" value of the next object with the ... Read More
We are required to write a JavaScript function that takes in an array of strings. The function should find all the substring and superstring combinations that exist in the array and return an array of those elements. For example − If the array is − const arr = ["abc", "abcd", "abcde", "xyz"]; Then the output should be − const output = ["abc", "abcd", "abcde"]; because the first two are the substring of the last one. How It Works The algorithm compares each string with every other string in the ... Read More
Problem We are required to write a JavaScript function that takes in an array of integers, arr, as the first argument and a single integer, target, as the second argument. For each integer in the array, our function can either assign '+' or '-' to it. Our function should find out how many ways in total exist to assign '+', '-' to make the sum of integers of the array equal to the target sum. For example, if the input to the function is: const arr = [1, 1, 1, 1, 1]; const target = ... Read More
Whenever an unexpected occurrence takes place in a JavaScript code, we need to debug it to check the cause. Debugging is a very important aspect of programming that lets you determine why a system or application behaves abnormally. It is a process of testing multiple times with different inputs and finding errors to reduce bugs from computer programs. In this article, we will be exploring the debugger keyword in JavaScript and how to use it. The debugger keyword in JavaScript is a common keyword used in debugging processes and variable inspection. When the debugger keyword is encountered and developer ... Read More
Tween.js is a JavaScript library that is mainly used when we want to tween or animate an HTML5 or JavaScript property. It can work standalone as well as when integrated with Easel.js. In this tutorial, we will learn how we can make use of Tween.js with the help of a few examples. Before we go on to the main example, let's first discuss a few simple tweens so that when we use them in the main example, you don't get overwhelmed. Simple Tween In this tween, we will tween the alpha property of the target from 0 ... Read More
We can create a Polygon object by creating an instance of fabric.Polygon. A polygon object can be characterized by any closed shape consisting of a set of connected straight line segments. Since it is one of the basic elements of FabricJS, we can also easily customize it by applying properties like angle, opacity etc. In order to find the rotation matrix, we use the _calcRotateMatrix() method. This method returns an Array with given values [cosA, sinA, -sinA, cosA, 0, 0] where A is the angle of rotation in degrees. Syntax _calcRotateMatrix(): Array Return Value ... Read More
We can create a Polyline object by creating an instance of fabric.Polyline while fabric.Polygon can be used to create a Polygon instance. A polyline object can be characterised by a set of connected straight-line segments. Since it is one of the basic elements of FabricJS, we can also easily customize it by applying properties like angle, opacity etc. A polygon always connects the first point to the last to make a closed area while a polyline doesn't. This can be proved by the examples given below. Syntax new fabric.Polyline(points: Array, options: Object) new fabric.Polygon(points: Array, options: ... Read More
In this article, we will learn to create an array from JSON data in JavaScript. JSON is a widely used format for storing and exchanging data. A common use case involves extracting specific data from a JSON object or array and converting it into a separate array for further processing. What is JSON Data? JSON (JavaScript Object Notation) is a lightweight data format commonly used to store and exchange data between a server and a client. It represents data as key-value pairs and is easy for both humans and machines to read and write. In JavaScript, JSON objects ... Read More
We are required to write a JavaScript function that takes two arrays, say arr1 and arr2. Our function should return a sorted array in lexicographical order of the strings of arr1 which are substrings of strings of arr2. How It Works The function iterates through arr1 and checks if each string is a substring of any string in arr2. If found, it adds the string to the result array and continues to the next string using a labeled continue statement. Example The code for this will be − const lexicographicalSort = (arr1 = [], ... Read More
In JavaScript, determining if two floating-point numbers are "approximately equal" is essential because of precision issues with decimal calculations. We compare the absolute difference between two numbers against a tolerance value called epsilon. Why Use Approximate Equality? Floating-point arithmetic can produce unexpected results: console.log(0.1 + 0.2); // 0.30000000000000004 console.log(0.1 + 0.2 === 0.3); // false 0.30000000000000004 false The Algorithm We calculate the absolute difference between two numbers and compare it with epsilon (tolerance). If the difference is less ... Read More