Harmony随笔01

1. Harmony中的基础类型，变量，常量，数组

// 1. 字符串
let title: string = '巨无霸汉堡'

// 2. 数字
let age: number = 28

// 3. 布尔
let isLogin: boolean = false

// 4. 定义一个常量
const PI: number = 3.1415926

// 5. 数组
let names: string[] = ['孙悟空','猪八戒','沙悟净']
console.log('数组names', names)
console.log('取数组', names[1])

2. 函数

// 1. 函数的定义
function buyFruit(price: number, num: number): number {
  let result: number = price * num;
  return result;
}

let apple = buyFruit(2.5, 2);
console.log("apple is", apple)

这个和kotlin很像

3. 箭头函数

// 1. 无参的箭头函数
let star = () => {
  console.log('无参的箭头函数')
}

star()

// 2. 有参的箭头函数
let buy = (price: number, num: number) => {
  let result: number = price * num;
  return result;
}

let banana = buy(2.5, 3);
console.log('banana is ', banana)

4. 对象

// 1. 先定义接口，再基于接口约定对象结构类型
interface Person {
  name: string
  age: number
  weight: number
}

// 2. 定义对象
let person: Person = {
  name: '杨幂',
  age: 32,
  weight: 100
}

console.log('name: ', person.name)

5. 定义对象的方法

let person: Person = {
  name: '杨幂',
  age: 32,
  weight: 100,

  // 无参数方法
  dance: (): void => {
    console.log('杨幂说', '我来跳个舞吧')
  },

  // 有参数方法
  sing: (song: string): void => {
    console.log('杨幂说', '我来唱首歌吧', song)
  }
}

console.log('name: ', person.name)

// 调用对象的方法
person.dance()
person.sing('爱的供养')

6. 联合类型

• 变量可以同时存储多种类型

// 1. 变量可以存储多种数据类型
let judge: number | string = 100
judge = "A+"
console.log("judge = ", judge)

// 2. 变量值预定在一组数据范围内
let gender: 'man' | 'woman' | 'secret' = 'man'
console.log('gender', gender)

7. 枚举类型

// 1. 定义枚举
enum ThemeColor {
  Red = '#FF0F29',
  Orange = '#FF7100',
  Green = '#30B30E'
}

// 2. 给变量设置枚举类型
let color: ThemeColor = ThemeColor.Orange

console.log('color', color)