函数声明

  1. function add(num1: number, num2: number): number {
  2.   return num1 + num2;
  3. }

函数表达式

  1. const add = function (num1: number, num2: number): number {
  2.   return num1 + num2;
  3. };

箭头函数

  1. const add = (num1: number, num2: number): number => {
  2.   return num1 + num2;
  3. };