Using Rest Parameters in TypeScript Functions

November 17, 2021 A Goodman

In TypeScript, you can use the spread operator (…) as the final parameter of a function. All of the arguments (except the ones that were explicitly declared before the three dots) passed to that function will…

TypeScript: Function with Optional and Default Parameters

November 17, 2021 A Goodman

In TypeScript, a function can have optional and default parameters. In order to make a parameter optional, we can postfix it with a question mark (?). We can provide a default value to a parameter by…

Calculate Variance and Standard Deviation in Javascript

November 15, 2021 The Plumber

This short article shows you how to calculate the variance and standard deviation of a given array of numbers. You will see the code in vanilla Javascript and TypeScript. Javascript Output: TypeScript If you use TypeScript…

Javascript: Capitalize the First Letter of Each Word (Title Case)

November 9, 2021 A Goodman

This short article shows you how to capitalize the first letter of each word in a string. hypothetical inputs and expected outputs: we will just capitalize the first letter of a word and keep the rest…

Express + TypeScript: Extending Request and Response objects

October 21, 2021 The Plumber

This article shows you how to add new properties to an Express request object (we often deal with this task when working with middleware) or an Express response (not too common but may be necessary in…

React + TypeScript: Working with Radio Button Groups

September 9, 2021 A Goodman

The end-to-end example below covers the most important aspects you need to know when working with radio button groups in a React application written in TypeScript. We will write code from scratch and use the modern…

React + TypeScript: Making a Custom Context Menu

September 7, 2021 A Goodman

This article walks you through an end-to-end example of creating a custom context menu in a React app that is written in TypeScript. We’ll use new features of React like hooks and functional components. You won’t…

React + TypeScript: Multiple Select example

August 31, 2021 A Goodman

The example below describes how to use a multiple select in a React project written in TypeScript. You will learn to get the selected values as well as display them on the screen. Everything will be…

React + TypeScript: onMouseOver & onMouseOut events

August 26, 2021 A Goodman

This article is about the onMouseOver and onMouseOut events in a React project written in TypeScript. We’ll go through the fundamentals of these events then examine a complete example of using them in practice. Overview The…

React + TypeScript: Image onLoad & onError Events

August 18, 2021 A Goodman

The end-to-end example below shows you how to handle image events in a React app that uses TypeScript. There are 2 events that we are going to work with: onLoad: This event occurs when an image…

React + TypeScript: Handling onClick event

August 17, 2021 A Goodman

The onClick event occurs when an element is clicked. This element can be a button, a div element, an image, etc. This article walks you through a couple of different examples of handling the onClick event…

React + TypeScript: Handling Keyboard Events

August 13, 2021 A Goodman

This article walks you through the basics and a few practical examples of handling keyboard events in a React app that is written in TypeScript. We’ll use modern React features including hooks and functional components. You…

1 2