ts 数组使用方式

概论

代码测试

// 普通数组
let uuy:Array<number>;

uuy=[23,23423,23423423]

let uud:[]

// let uua:array; //报错，不能这样声明数组

//从右往左是越子级内容
let uuv:number[][] //二维数组

uuv=[[23,23423,23423423],[23,23423,23423423],[23,23423,23423423]]

let uuo:Array<number>[]

uuo=[[23,23423,23423423],[23,23423,23423423],[23,23423,23423423]]

let uup:object[]

uup=[[23,23423,23423423],[23,23423,23423423],[23,23423,23423423]]
uup=[{a:23,b:23423,c:234}]
// in 只能用于映射类型且只能用于对象的key 映射，如下方式使用
let uum:{[k in ('a' | 'b' | 'c')]:any}[]

uum=[{a:23,b:23423,c:23}]

type UunKey="a" | "b" | "c"
let uun:{[k in UunKey]:any}
/**
 * let uun: {
    a: any;
    b: any;
    c: any;
}
 */


uun={
  a:23,
  b:23423,
  c:234
}


// k in string 代表任意字符类型都可以作为key
let uui:{[k in string]:any}

uui={
  a:23,
  b:23423,
  c:234,
  d:3234234
}

let uuh:{[k in number]:any}
uuh={
  0:23,
  1:23423,
  2:234,
  3:3234234
}

let uuq:{[k:number]:string | number | symbol}

uuq={
  0:23,
  1:23423,
  2:234,
  3:3234234
}

/**
 * 元组只能固定长度，且每个元素类型都要声明
 */
//元组数组
let uuc:[string,number,boolean];

uuc=["a",23,true]

// 1. 使用方括号语法
let numbers1: number[] = [1, 2, 3, 4, 5];

// 2. 使用泛型数组类型
let numbers2: Array<number> = [1, 2, 3, 4, 5];

// 3. 使用 Array 构造函数
let numbers3: number[] = new Array(1, 2, 3, 4, 5);
let emptyArray: any[] = new Array();

// 4. 使用 Array.of 方法
let numbers4: number[] = Array.of(1, 2, 3, 4, 5);
let mixedArray1: any[] = Array.of(1, "a", true);

// 5. 使用 Array.from 方法
let arrayLike: number[] = Array.from({ length: 5 }, (_, index) => index + 1);
let set: Set<number> = new Set([1, 2, 3]);
let numbers5: number[] = Array.from(set);

// 6. 使用类型断言
let mixedArray2 = [1, "a", true] as (number | string | boolean)[];
let strings = ["a", "b", "c"] as string[];

// 7. 创建多维数组
let twoDimensionalArray: number[][] = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
];

let threeDimensionalArray: number[][][] = [
  [
    [1, 2, 3],
    [4, 5, 6]
  ],
  [
    [7, 8, 9],
    [10, 11, 12]
  ]
];

// 8. 使用 ReadonlyArray 类型
let readonlyNumbers: ReadonlyArray<number> = [1, 2, 3, 4, 5];