Author: Saim Khalid

The var keyword in JavaScript is used to declare variables. Before ES6, there was only var keyword to declare a variable. In ES6, let and const keywords were introduced as a better way to declare variables. It is advised to use let instead of var to declare a variable. If you are targeting older version of browser, you can…

The new keyword in JavaScript is used to create an instance of the object that has constructor function. Using new keyword, we can create the instances of a user-defined as well as built-in object types. We can create instances of the classes, prototype, or constructor functions. When a JavaScript function is called with new keyword, the function…

The void keyword in JavaScript is used as an operator that evaluates a given expression and returns undefined. The void is an important keyword in JavaScript. The meaning of the void is null or empty. The void keyword can be used as a unary operator that appears before its single operand, which may be of any type. This operator specifies an expression to be evaluated without returning…

What is ‘this’ keyword? In JavaScript, the ‘this‘ keyword contains the reference to the object. It represents the context of the function or current code. It is used to access the properties and methods of the current object. When this keyword is used inside a function, the this will refer to the object that the…

The custom errors in JavaScript are errors that you create yourself, as opposed to the built-in errors that JavaScript throws. You can create custom errors to handle specific types of errors that may occur in your code. To create a custom error, you can use the Error constructor. The Error constructor takes a string as its argument, which…

Custom errors are a way to create user-defined error types in JavaScript. This can be useful for handling specific types of errors, such as database errors or HTTP errors. JavaScript contains multiple built-in objects for the errors. Whenever any error occurs in the JavaScript code, it throws an instance of the Error class. However, you can…

What is Debugging? Debugging in JavaScript is a process of examining JavaScript code and finding erros and fixing them. Every now and then, developers commit mistakes while coding. This error can be logical, syntax, or runtime errors. An error in a program or a script is referred to as a bug. The process of finding…

JavaScript try…catch Statement The try-catch statement in JavaScript is used to handle the runtime errors (exceptions). This is very common in most programming languages to handle exceptions. A try-catch statement can handle only runtime errors. The try block must be followed by either exactly one catch block or one finally block (or one of both). Inside the try{}…

Error handling in JavaScript is a process to detect and handle errors that occurs during the execution of a program. Errors can be a syntax, runtime or logical errors. An error occurred during the execution of the program is called a runtime error or an exception. In JavaScript, errors can occur due to programming mistakes,…

Custom Events The custom events in JavaScript define and handle custom interactions or signals within an application. They establish a communication mechanism between various sections of your code: one part can notify others about specific occurrences or changes; thus enhancing the functionality of your program. Typically, users utilize custom events in conjunction with the Event…