Have you come across a requirement to merge two or more object in another object? Most simply, you can achieve it by using JavaScript Spread syntax (…). Due to its multi functionalities purpose, JavaScript Spread Syntax is one of the most useful operators. You can use it, Rest parameters to a functionTo merge two andContinueContinue reading “Using Spread Syntax to Merge Objects in JavaScript”
Category Archives: JavaScript
Four Ways to Create a Function in JavaScript
There are four ways a function can be created in JavaScript. They are as follows: A function as a statementA function as an expressionA function as an arrow functionA function created using the Function constructor All four ways of function creation have distinct features such as an arrow function that does not have its own this object,ContinueContinue reading “Four Ways to Create a Function in JavaScript”
A JavaScript function inside a Block Scope: Simplified
Scoping determines the visibility of a variable, an object, or a function. For example, a variable defined inside a function is visible or can be accessed only inside that particular function. JavaScript has 4 types of scope. Global scopeFunctional scopeLexical ScopeBlock Scope Out of the above four scoping, Block Scoping became part of JavaScriptContinueContinue reading “A JavaScript function inside a Block Scope: Simplified”
How to manually pass the value of ‘this’ object in a JavaScript function
Every JavaScript function has a ‘this’ object, and the value of ‘this’ object depends on the way you call the function. To pass the value of ‘this’ manually, you need to call the function indirectly. In JavaScript, you call a function indirectly to pass the value of ‘this’ object manually. Manually calling a function isContinueContinue reading “How to manually pass the value of ‘this’ object in a JavaScript function”
How to make a property non-enumerable in JavaScript?
By default, all the properties of JavaScript objects are enumerable. That means you can enumerate them in a for loop or read them using the Object.values(). Let us consider an object Dog as shown below, let Dog = { name :’foo’, age: 9, canRun : true, eatMilk : false } You can enumerate all propertiesContinueContinue reading “How to make a property non-enumerable in JavaScript?”
How to merge arrays using spread operator in JavaScript?
Have you come across a requirement to merge two or more arrays into another array? Let us say, you have two arrays as shown below, const metrocities = [‘Delhi’, ‘Mumbai’,’Chennai’,’Bangalore’,’Hyderabad’]; const smallcities = [‘Jamshedpur’,’Pune’,’Lucknow’,’Trivandrum’]; You need to merge them in another array with optional extra elements in the resultant array. JavaScript array spread operator makesContinueContinue reading “How to merge arrays using spread operator in JavaScript?”
How to create Private Properties in JavaScript.
We don’t have Access Modifiers in JavaScript, and all properties of an object are public, which means you can read and modify them outside the object. But what if you have a requirement to create private properties? Consider Product object as mentioned below, let Product = { id: ‘1’, price: 200, title: ‘Pencil’ } console.log(Product.id);ContinueContinue reading “How to create Private Properties in JavaScript.”
Explain Object.keys in JavaScript
Enumerating through the properties of a JavaScript object is a persistent requirement. Hence it becomes a popular question in a JavaScript interview. Any good JavaScript developer must know about various available options. Note: You can find a video tutorial on the same at the end of the article. To start with considering the Dog objectContinueContinue reading “Explain Object.keys in JavaScript”
Five Things about JavaScript delete operator
A better understanding of delete operator is necessary for JavaScript developers. As the name suggests, the delete operator deletes properties from the object. You can delete a property as shown below: It returns true on successful deletion. However, in some cases, it may return true even if it does not delete a property. In thisContinueContinue reading “Five Things about JavaScript delete operator”
All about NaN in JavaScript
In JavaScript, NaN is one of the most confusing concepts; hence, it is often asked in the interview. You may have come across questions such as, What is NaN What is the type of NaN How to check for the NaN What is the difference between isNaN() and Number.isNaN() In this post, let us learnContinueContinue reading “All about NaN in JavaScript”
Dhananjay Kumar 