angular variable function type code example

Example 1: typescript arrow function

let sum = (x: number, y: number): number => {
    return x + y;
}

sum(10, 20); //returns 30

Example 2: get function return type typescript

type return_type = ReturnType<() => string>; // string
// or
function hello_world(): string {
  return "hello world";
}
type return_type = ReturnType<typeof hello_world>; // string