HarmonyOS/鸿蒙.learn/NEXT 星河版-黑马/01.基础前提.md

# 基础语法

### 基础数据类型的定义

```tsx
//字符串类型
let title: string = '急急急'
//number
let age: number = 18
//boolean
let isLogin: boolean = true


//常量
const PI: number = 3.1415926
```



### 数组

```tsx
let names: string[] = ['jack','li','wang']
```





### 函数



```tsx
function 函数名(形参:类型){
    函数体
    return
}
//箭头函数
let 函数名 = () =>{
    //函数体
}
```





### 对象



```tsx
//定义对象并使用
//1. 定义接口
interface Person{
    name: string
    age: number
    weight: number
    dance: (i: number) =>{
        console.log('ming跳了',i,'次舞')
    }
}

//基于接口，定义对象
let ym: Person = {
    name: 'ming',
    age: 18,
    weight: 90
}

//获取对象属性值 对象名.属性名
console.log('体重：',ym.weight)

```



### 联合类型

```tsx
let judge: number|string = 100
judge = 'A'
```



### 枚举

```tex
//约定变量只能在一组数据范围中选择值

enum ThemeColor{
Red = '#ffof29'
Orange = '#ff7100'
Green = '#30b30e'
}
//引用后color只能在ThemeColor中取值
let color: ThemeColor = ThemeColor.Red
```