different-variables-types

In JavaScript, you can assign any value to any variable. But in TypeScript, a variable's type is generally fixed. Using different variables for different concepts improves type safety and code clarity.

Union types are harder to work with and obscure the code's intent.

const makes code easier for both humans and TypeScript to understand.

변수를 재사용하고 싶을 때 사용하세요. 변수의 유형이 변경될 때 사용합니다. 여러 목적으로 공용체 유형을 사용할 때 사용합니다. 출처: marius-townhouse/effective-typescript-skills.