1.typescript基础类型

官网： https://www.tslang.cn/docs/handbook/basic-types.html

• 1.字符串：string
• 2.浮点类型，数字：number
• 3.布尔值：boolean
• 4.数组：Array<number> || number[] || ReadonlyArray<number> （只读数组）
• 5.元组：[number,string] tuple
• 6.枚举：enum
• 7.任何类型：any
• 8.没有任何类型：void
• 9.Null 和 Undefined
• 10.非原始类型：object
• 11. never

// string 
let name1: string = 'hahahha';
console.log(name1); //hahahha

// number 
let name2: number = 30;
console.log(name2);//30

// boolean 
let name3: boolean = true;
console.log(name3);//true

// array 
let name4: number[] = [2];
let name5: Array<String> = ['2'];
console.log(name4);//[2]
console.log(name5);//['2']
let nameArr: ReadonlyArray<number> = [2];
nameArr[1] = 3; // Index signature in type 'ReadonlyArray<number>' only permits reading.
 
// 元组 tuple 
let name6: [number,string,object,boolean];
name6 = [3,'3',{},true];
console.log(name6);

// enum
enum List{One =2,Two=4};
let name7: List = List.One;
let ListName: string = List[4];
console.log(name7);
console.log(ListName);

// any
let name8: any = 'sdf';
console.log(name8);
name8 = 34;
console.log(name8);
let na:number | undefined;
na = undefined;

// void 
function myvoid ():void{
    console.log('void');
}
myvoid();
let myvoidtype: void = null;
console.log(myvoidtype);
myvoidtype = undefined;
console.log(myvoidtype);

// null && undefined
let name9:null = null;
let name10: undefined = undefined;
console.log(name9);
console.log(name10);

// object
let name11: object = {};
console.log(name11);