本篇List

1）概念

ts支援與js相同型別的資料型別，此外還提供了列舉等型別

2）字串

let dogName: string = "linda";
let dogAge: number = 12;
let introDog: string = `我有一隻狗他${dogAge}`;

3) 數字

//2.數字
// 2, 8, 10, 16
let num1: number = 16;
let num2: number = 0x10;
let num3: number = 0o20;
let num4: number = 0b10000;

4) 布林

//3.布林
let flag:boolean = true || false
 

5) 陣列

//4.陣列
let numArr: number[] = [1, 2, 3];
let stringArr: string[] = ["linda", "dali"];
let boolArr: Array<boolean> = [true, false];

6) 元祖

//5.元祖
let tuple: [string, number, boolean, string];
tuple = ["linda", 25, true, "good"];

7) 列舉

// 6.列舉,也是ts中的基本型別之一
enum Sex {
    woman,
    man
}

let sex1: Sex = Sex.woman
let sex2: Sex = Sex.man

console.log(sex1, sex2) // 1, 0

// 手動賦值 , 此時man的值就為 2， 根據上一個加來的
enum SexB {
    woman= 1,
    man
}

//根據列舉 的值取名字
let sexName: string = SexB[1]
console.log(sexName) // woman
 

8）void

//9.void
function logMsg() :void{
    console.log(123)
}

9）null undefined

10) never

// 10. never
//必須存在無法到達的終點
//例如丟擲異常的函式
function errMsg(msg: string): never {
    throw new Error(msg)
}
function errMsg2(msg: string): never {
   while (true) {
       console.log(123)
   }
}

11）object

// 11.object
function objMsg(msg: object) {
    console.log(msg)
}
let obj:object  = {name: 1, sex: 'woman'}
let obj2:object = [1, 5, 8, 10, 4]
 

12）斷言

// 12.型別斷言
let strA:any = [1, 2, 3]
let strC: string = (<string>strA).substr(1, 2)
let strD :string = (strA as string).substr(1, 3)

13）生明

14) 解構