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 <T>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 <T>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));}}