// 基本定义
let arr:number[] = [1,2,3];
let arrS: string[] = ["1","2"]

var arr:number[] = new Array(10);  
for(var i = 0; i<arr.length; i++) { 
    arr[i] = i * 2 
    console.log(arr[i]) 
}

let arr1:Array<number> = [1,2,3,4,5]
let arr2:number[] = new Array(1,2,3);
console.log("arr1===="+arr1);
console.log("arr2===="+arr2);

var arr_name:datatype[][]=[ [val1,val2,val3],[v1,v2,v3] ]

var arr:number[][] = [[1,2,3],[4,5,6]]  
console.log(arr[0][0]) 
console.log(arr[0][1]) 
console.log(arr[0][2]) 
console.log(arr[1][0]) 
console.log(arr[1][1]) 
console.log(arr[1][2])

// 声明多维数组
let arr:number[][] = [[1,2,3], [4,5,6]];
// 泛型形式声明多维数组(联合类型)
let arr1:Array<Array<number | string>> = [[1,2,3,"123"],[4,5,6,"789"],[]];
console.log(arr)
console.log(arr1)

// 类数组
function Arr(... args:any):void{
    console.log(arguments) //类数组,arguments是参数
    let arr:IArguments = arguments  //用IArguments去接收
}
Arr(1,2,3)  //[Arguments] { '0': 1, '1': 2, '2': 3 }

// 数组解构
var arr = [12, 13];
var x = arr[0], y = arr[1]; // 将数组的两个元素赋值给变量 x 和 y
console.log(x);
console.log(y);

// 通过接口描述数组
interface NumberArray{
    [index:number]:number;  //只要索引的类型是数字，那么值的类型也必须是数字,换成string也是一样的
}
let arr:NumberArray = [1,2,3];
console.log(arr);

// 数组迭代
var j:any; 
var nums:number[] = [1,2,3,4] 
for(j in nums) { 
    console.log(nums[j]) 
}