Function Parameter Types

Snippet

In TypeScript, you can specify types for both function parameters and the value the function returns.

snippet.ts
typescript
function greet(person: string): string {
  return "Hello, " + person;
}
 
const message = greet("Anna");

Breakdown

person: string

The function expects one argument, which must be a string.

): string {

The colon after the parentheses indicates the function will return a string.

greet("Anna")

Calling the function with a valid string argument.

From your library