數組逆序

package com.test;
import java.util.Arrays;
public class Test {
    public static void main(String[] args){
        int[] arr = {1,2,3,4,5,6,7};
        reverse(arr);  //調用逆置數組方法
        System.out.println(Arrays.toString(arr));
    }
    //逆置數組方法
    public static void reverse(int[] arr){
        int left = 0;  //left取數組最左邊元素下标
        int right = arr.length - 1;  //right取數組最右邊元素下标
        while (left < right){
            //交換下标為left和right的兩個元素的值
            int temp;
            temp = arr[left];
            arr[left] = arr[right];
            arr[right] = temp;
            left++;  //left加1
            right--;  //right減1
        }
    }
}