public static void main(String[] args) {
        int[] arr = new int[]{34, 23, 56, 21, 19,68,10};
        System.out.print("反轉前：");
        
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i]+" ");
        }
        
        for (int minIndex = 0, maxIndex= arr.length-1;minIndex<maxIndex;minIndex++,maxIndex--) {
            
 
int temp = arr[minIndex];
            arr[minIndex]=arr[maxIndex];
            arr[maxIndex]=temp;
        }
        
        System.out.println(" ");
        
        System.out.print("反轉後: ");
        
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i]+" ");
        }
    }