TypeScript is more and more common when writing code for modern JavaScript. In my current work project, we have started using it for a while though not fully migrated it from JavaScript to TypeScript yet. However, it’s still a good opportunity to catch this up.

I learned two following courses in February:

• https://www.executeprogram.com/courses/typescript-basics
• https://www.executeprogram.com/courses/everyday-typescript

They’re both excellent and I am looking forward to learn the advance course from them. They use the format of giving explanations, then examples, and finally reviews after that. It’s also very good at going deep-dive and answering multiple questions “why” TypeScript makes a specific decision as well as how to avoid mistakes, overcome specific limitations, etc.

Even so, I will consider taking this Udemy course to how to fit TypeScript into a specific project, especially a large project or a non-fresh project with some existing JavaScript code. And to apply some of these knowledge, I would like to refactor my side project currency-conversion to TypeScript too.

I have been confused and used the wrong term too, so here it is:

An important note: you’ve probably heard the terms “parameters” and “arguments” used interchangeably. Then why is this type called Parameters and not Arguments? The reason is that the two words have different meanings when we talk about programming languages in a formal way.

A parameter is part of a function’s definition, like the n in function double(n: number). An argument is a value that we pass when calling a function, like the 5 in double(5). Many programmers call both of these “arguments” in everyday conversation. Compilers and other programming language tools like TypeScript need to avoid ambiguity, so they usually distinguish between parameters and arguments.

https://www.executeprogram.com/courses/everyday-typescript/lessons/returntype-and-parameters