Taking this course:

React & TypeScript - The Practical Guide

What we’ve learnt:

02. Basics and Core Concepts

Type checking, type inference, explicit type annotations.

Primitive types: string, number, boolean. No int nor float or their signed/unsigned and floating point accuracy variants distinction?

Compiling ts code: tsx tsc app.ts →returns app.js , with let → var . Not used a lot.

Union of types.

object type.

Array type.

Cannot reassign value to a const.

functions.

void type for functions that dont return a value.

for functions that will be passes as an argument to another function, use function type definition/signature. example: calcFn: (a: number, b: number) => number

or we can define a custom type, by using type, for example:

type AddFn: (a: number, b: number) => number;

so in the other functions that use that function as parameter, the type of the parameter inside the function definition will be like this: calcFn: AddFn

we can also define custom type for any composite types, such as

type StringOrNum = string | number

i will skip interface, too much brain memory load.