Generic arrow functions in TypeScript
October 23, 2023
In TypeScript, generics allow developers to write flexible and reusable components while still maintaining type safety. Combined with arrow functions, you can create concise, type-safe utility functions and callbacks. In this guide, we'll explore how to use generic arrow functions in TypeScript.
Basics of TypeScript Generics
Generics in TypeScript provide a way to create reusable components that work over a variety of types rather than a single one.
In this example, the function
identity has a single type parameter
T. This means it can be called with any type and will return a value of that same type.
Arrow Functions in TypeScript
Arrow functions provide a concise syntax to represent anonymous functions. Here's the basic syntax:
Combining Generics with Arrow Functions
Now, let's combine both concepts. Here's how you can write a generic arrow function:
This is essentially the same
identity function we looked at earlier but written as an arrow function.
Swapping Tuple Values
Suppose you want to write a type-safe function to swap the values in a 2-tuple. Here's how you can do it using a generic arrow function:
Mapping Array Values
Consider a function that maps over an array and returns the results. Here's a generic version of it:
Type Constraints with Generic Arrow Functions
Sometimes, you might want to limit the types that can be passed to a generic function. This is achieved using type constraints.
For instance, suppose you want to ensure that the type has a
You wouldn't be able to call
getLength with a number or boolean, since they don't have a
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