YouTube Summaries | Why Use Type and Not Interface in TypeScript

October 30th, 2023

TL;DW:

• Type Aliases:

  • More versatile than interfaces.
  • Describe primitives, union types, and tuples.
  • Offer predictability and cleaner code.

• Interfaces:

  • Provide focused error messages.
  • Useful for library development.

Reasons to Prefer Type Aliases over Interfaces

1. Type aliases can describe primitive values (string, number, boolean), while interfaces are limited to describing objects.
2. Type aliases allow for the creation of union types and can use utility types more cleanly.
3. Type aliases can describe tuples with cleaner syntax.
4. Type aliases are more predictable and prevent unexpected changes, as opposed to interfaces that can be merged or redeclared, potentially causing confusion.
5. Type aliases work well with classes and the implements keyword.
6. Type aliases are shorter in terms of character count compared to interfaces.

Specific Use Cases for Interfaces

1. Interfaces may provide more focused error messages.
2. Interfaces can be merged, which can be useful in library development.