let array1:Array<number>;
let array2:number[];

let array1:Array<number> = new Array<number>();
let array2:number[] = [1，2，3];

let array:Array<number> = [1,2,3,4];
console.log(array) ? ? ?// [1, 2, 3, 4]

array[0] = 20; ? ? ? ? ?// 修改
console.log(array) ? ? ?// [20, 2, 3, 4]

array[4] = 5; ? ? ? ? ? // 賦值
console.log(array) ? ? ?// [20, 2, 3, 4, 5]

array.push(6); ? ? ? ? ?// 添加
console.log(array) ? ? ?// [20, 2, 3, 4, 5, 6]

array.unshift(8, 0); ? ?// 在第一個位置依次添加
console.log(array); ? ? // [8, 0, 20, 2, 3, 4, 5, 6]

let array:Array<number> = [1,2,3,4];
console.log(array) ? ? ?// [1, 2, 3, 4]

let popValue = array.pop(); ? ? // 彈出
console.log(array) ? ? ?// [1, 2, 3]

array.splice(0, 1); ? ? // 刪除元素（index, deleteCount）
console.log(array) ? ? ?// [2, 3]

array.shift(); ? ? ? ? ?// 刪除第一個元素
console.log(array); ? ? // [3]

/**
? * Combines two or more arrays.
? * @param items Additional items to add to the end of array1.
? */
concat(...items: T[][]): T[];
/**
? * Combines two or more arrays.
? * @param items Additional items to add to the end of array1.
? */
concat(...items: (T | T[])[]): T[];
/**
?* 該方法返回指定起始位置的一個新的數(shù)組
?*/
slice(start?: number, end?: number): T[];

let array: Array<number> = [1, 2, 3];
let array2: Array<number> = [4, 5, 6];
let arrayValue = 7;
array = array.concat( array2);
console.log(array) ? ? ? ? ?// [1, 2, 3, 4, 5, 6]

array = array.concat(arrayValue);
console.log(array) ? ? ? ? ?// [1, 2, 3, 4, 5, 6, 7]

let newArray = array.slice(2, 4);
console.log(newArray) ? ? ?// [3, 4]

/**
? * 返回查找到的第一個元素所在位置
? */
indexOf(searchElement: T, fromIndex?: number): number;
/**
? * 返回反序查找的第一個元素所在位置
? */
lastIndexOf(searchElement: T, fromIndex?: number): number;


let array: Array<string> = ["a","b","c","d","c","a"];
let indexC = array.indexOf("c");
console.log(indexC); ? ? ? ? ? ?// 2
let lastA = array.lastIndexOf("a");
console.log(lastA); ? ? ? ? ? ? // 5

/**
?* 連接數(shù)組
?*/
join(separator?: string): string;

let array: Array<string> = ["a","b","c","d","c","a"];
let result = array.join();
console.log(result); ? ? ? ? ? ?// a,b,c,d,c,a

result = array.join("+");
console.log(result); ? ? ? ? ? ?// a+b+c+d+c+a

result = array.join("");
console.log(result); ? ? ? ? ? ?// abcdca

let array:Array<number> = [3, 2, 1, 8, 7, 0, 4];
console.log(array); ? ? ? ? ? ? // [3, 2, 1, 8, 7, 0, 4]

array.sort();
console.log(array); ? ? ? ? ? ? // [0, 1, 2, 3, 4, 7, 8]

array.reverse();
console.log(array); ? ? ? ? ? ? // [8, 7, 4, 3, 2, 1, 0]