typescript function that takes a function code example

Example 1: types function typescript

interface Safer_Easy_Fix {
    title: string;
    callback: () => void;
}
interface Alternate_Syntax_4_Safer_Easy_Fix {
    title: string;
    callback(): void;
}

Example 2: typescript pass a function as an argunetn

class Foo {
    save(callback: (n: number) => any) : void {
        callback(42);
    }
}
var foo = new Foo();

var strCallback = (result: string) : void => {
    alert(result);
}
var numCallback = (result: number) : void => {
    alert(result.toString());
}

foo.save(strCallback); // not OK
foo.save(numCallback); // OK

Example 3: typescript function type

interface Date {
  toString(): string;
  setTime(time: number): number;
  // ...
}

Example 4: typescript function

// Named function
function add(x: number, y: number): number {
  return x + y;
}

// Anonymous function
let myAdd = function (x: number, y: number): number {
  return x + y;
};