typescript-3.7.5.tar.gz

TypeScript 3.7.5 Strict

TypeScript 3.7.5

Are you using TypeScript, but feel like you’re not making the most out of it? Do you find some advanced TypeScript concepts confusing? Do you get lost looking at complex type errors?

If you answered “yes” to any of these questions, then this course is for you! It introduces you to the world of advanced TypeScript concepts including: compiler flags for catching more errors, generic types, and how to compose types with discriminated unions. 

After finishing this course, you’ll feel more confident in your TypeScript skills. You will be able to write types that detect whole classes of possible runtime errors at compile time. Typing even the most untypeable JavaScript code will be a no brainer for you, and you’ll be fluent in TypeScript error messages.

Advanced TypeScript Masterclass

## Structural vs nominal typing

The majority of programming languages traditionally associated with static typing (Java, C#, C++) follow an approach called _nominal typing_. In a nominal type system every type is unique. Imagine that you have created two interfaces with exactly the same properties. In TypeScript, it's perfectly fine to assign an instance of one of these interfaces to a variable typed using the other one. However, in languages with nominal typing, that wouldn't be possible. TypeScript doesn't use nominal typing, instead is uses _structural typing_.

# Structural vs nominal typing

The majority of programming languages traditionally associated with static typing (Java, C#, C++) follow an approach called _nominal typing_. In a nominal type system every type is unique. Imagine that you have created two interfaces with exactly the same properties. In TypeScript, it's perfectly fine to assign an instance of one of these interfaces to a variable typed using the other one. However, in languages with nominal typing, that wouldn't be possible. TypeScript doesn't use nominal typing, instead is uses _structural typing_.

This lesson talks about nominal types, a concept that is not part of TypeScript, but can be emulated easily.

Strict types

Generics

Composing types

Advanced types

TypeScript in practice

Conclusion

Nominal Types

Structural vs nominal typing