JavaScript

Mutability refers to whether an object’s state can be changed after it’s created. Mutable objects can be changed; immutable ones cannot. Understanding mutability is essential because JavaScript treats primitives and objects very differently. A Quick Look at the Examples a. What is Mutability? Mutability refers to whether an object’s state can be changed after it’s…

Strings in JavaScript are immutable sequences of characters. JavaScript provides a rich set of built-in methods to work with strings — extracting, transforming, searching, and manipulating text. A Quick Look at the Examples a. String Properties — Part 1 Character & Code Methods Method Description Example Result String.fromCharCode(…) Returns string from char codes String.fromCharCode(65, 66,…

Rest parameters provide a way to handle an indefinite number of arguments as an array. They were introduced in ES6 (ECMAScript 2015) and offer a more concise syntax for working with functions that accept a variable number of arguments. A Quick Look at the Examples a. Rest Parameters Introduction Rest parameters provide a way to…

Destructuring assignment is a feature that allows you to extract data from arrays or objects into variables. It uses syntax that looks similar to array or object literal notation, making your code more concise and readable. A Quick Look at the Examples a. Introduction and Array Destructuring Destructuring assignment allows you to extract data from…

The Math object in JavaScript is a versatile tool for performing a wide range of mathematical operations. It provides everything you need to handle most mathematical tasks — from basic arithmetic and rounding to advanced functions like trigonometry and random number generation. Note: Math is a built-in object — you don’t need to create it,…

JSON is a lightweight data interchange format — easy for humans to read and write, and easy for machines to parse and generate. It’s the standard for sending data between a client and a server. A Quick Look at the Examples a. What is JSON? JSON (JavaScript Object Notation) is a lightweight data interchange format….

Higher-order functions (HOFs) are functions that take other functions as arguments or return them as results. They’re a core concept in functional programming and allow for more flexible and reusable code. A Quick Look at the Examples a. What is a Higher-Order Function? Higher-order functions (HOFs) are functions that take other functions as arguments or…

Encapsulation is one of the fundamental concepts in object-oriented programming (OOP). It’s used to restrict access to some of an object’s internal state — protecting data integrity, managing complexity, and promoting maintainability by allowing controlled access to internal properties and behaviors. A Quick Look at the Examples a. What is Encapsulation? Encapsulation is the practice…

A prototype is a mechanism that allows you to add properties and methods to objects. Every JavaScript function has a prototype property, which refers to an object known as the prototype object — a template from which all instances of the function’s objects are created. A Quick Look at the Examples a. What is the…

A class is a blueprint for creating objects. It encapsulates data (properties) and functions (methods) that operate on the data. Classes provide a clean, modern syntax for object-oriented programming in JavaScript. A Quick Look at the Example a. Classes — Part 1 A class is a blueprint for creating objects. It encapsulates data (properties) and…