TypeScript or JavaScript?

Not in terms of TypeScript. I'm trying to sensitize people into to understand to have a code that is studying of JavaScript as well and understand that there are relationships between the two. Once you write your code in types, you're going to run in JavaScript. But if you can understand how it's going to behave at runtime, then you'll know what to expect. And also understanding the typing system for both of them because TypeScript is a static type. So JS is weakly dynamically typed but still allows you to know still if you don't do your validations at Runtime.