typescript type functions code example

Example 1: typescript function type

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

Example 2: types function typescript

interface Easy_Fix_Solution {
    title: string;
    callback: Function;
}

Example 3: types function typescript

interface Better_still_safe_but_way_more_flexible_fix {
    title: string;
    callback: <T = unknown, R = unknown>(args?: T) => R;
}
interface Alternate_Syntax_4_Better_still_safe_but_way_more_flexible_fix {
    title: string;
    callback<T = unknown, R = unknown>(args?: T): R;
}

Example 4: typescript annotate return type

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