Do You Need to Learn TypeScript in 2023?

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What's This One About?

On top of the growing collection of "must-know" tools in a web developer's arsenal is the famous (or maybe infamous?) TypeScript - a high-level programming language that adds static typing with optional type annotations to JavaScript. Developed by Microsoft, TypeScript can improve the developer experience by allowing the data that is passed around the code to be typed to something specific (ie Boolean), with TypeScript ready to throw an error if the types don't match appropriately through the program. In this episode, Matt and Mike discuss TypeScript at length discussing whether you need to learn TypeScript and how to learn it whether you're a beginner, or veteran coder.

Show Notes

What is TypeScript?

A way to add static types, classes, and interfaces to JavaScript
Catch code errors at compile time
Upgrades your tooling to allow for auto-complete and easy refactorablity

TypeScript Basics

Static Typing
- JavaScript uses dynamic typing where a variable can be set to any type. A string, number boolean, function, etc.
- TypeScript adds the ability to set what variable should be set to. Example
  - Let numA: number
  - Let isShowing: boolean
- You can also have variables of multiple types using an intersection
  - String | undefined
- Any is used when you don’t know what the type will be. Use these never
Interfaces and Classes
- Both are object-oriented principles
- Interfaces are good for creating shapes for your objects that can be merged/extended
  - Interface Person {firstName: string, lastName: string}
  - Interface athlete inherits Person { height: number, sport: string}
- Classes can also be used in a similar way to interfaces but with the added functionality of creating constructors and methods.
Generics
- Reusable components that can work over a variety of types while maintaining type safety.
- These types/functions can be used in a variety of ways where defining static types doesn’t make sense
  - Creating a function that will be accepting multiple different types and return different types
  - Example a function using a generic that returns the first element of an array. Could work with any element and return it in a type-safe way as when you instantiate the array and use the function the type can be inferred from the array you created
Type Inference
- A lot of times in TypeScript you might not even have to statically declare or type a variable because it can infer type from when you instantiate it.
  - Ex. let myName = “mike”
    - myName will be inferred as a String
TypeScript Compiler
- Since TypeScript is not understood by the browser we need to use the tsc, Typescript Compiler. It will continually run while you’re developing to check for code/type errors. The compiler can be configured with a tsconfig.json file

Do you need to know TypeScript?

TypeScript has started to become a standard in the web development space
With that most job postings I’ve recently checked in my area have listed it as part of the required or recommended skills
If you’re looking for a job it might be a good idea to dive into TypeScript, maybe take a short course from Matt Pocock and try to convert one of your existing JavaScript projects to TypeScript
You SHOULD NOT try to learn all of the ins and outs of TypeScript before applying for a job.
- A good handle on Static Typing, Generics, and Type Inference should be enough to jump in.
- You’ll learn more when you start working on a large TypeScript project than by reading/watching tutorials. Employers usually know this*
Do you need TypeScript for your side projects?
- It depends on what your goals are, if you’re the only one working on it and it is just a way for you to create your side hustle, you probably don't need TypeScript
- If your goal is to use the project as a portfolio piece and to get a job, then TypeScript is probably a good idea, regardless of the size of the project