编写一个数组的工具类

package com.zyf.day16;
/**
 * 需求:编写一个数组的工具类
 * @author root
 *
 */
class MyArrays{
	//元素反转
	public void reverse(T[] arr){
		for(int startIndex = 0,endIndex = arr.length -1;startIndex < endIndex;startIndex++,endIndex--){
			T temp = arr[startIndex];
			arr[startIndex] = arr[endIndex];
			arr[endIndex] = temp;
		}
	}
	
	public String toString(T[] arr){
		StringBuilder sb = new StringBuilder();
		for(int i = 0;i < arr.length;i++){
			if(i==0){
				sb.append("[" + arr[i] + ",");
			}else if(i == arr.length -1){
				sb.append(arr[i] + "]");
			}else{
				sb.append(arr[i] + ",");
			}
		}
		return sb.toString();
	}
}
public class demo3 {
	public static void main(String[] args){
		Integer[] arr = {10,12,14,19};
		//创建了数组的工具类对象
		MyArrays arrTool = new MyArrays();
		
		arrTool.reverse(arr);
		System.out.println(arrTool.toString(arr));
	}

}