What are the differences between type annotations and type checking?

What are the differences between type annotations and type checking?

Type annotations are explicit declarations of variable types in code, while type checking is the process of verifying those types during compilation or runtime.

Can you give me an example of type annotations?

Sure! In Python, you might write def add(a: int, b: int) -> int: to indicate that a and b are integers and the function returns an integer.

And how does type checking work in practice?

Type checking can occur at compile time, like in statically typed languages (e.g., Java), or at runtime in dynamically typed languages (e.g., Python) using tools like mypy.

Why is type checking important?

Type checking helps catch errors early, improves code readability, and enhances maintainability by ensuring that variables are used consistently.