import java.util.Scanner;
class ReverseArray 
{
    public static void main(String[] args) 
    {
        int[] arra = new int[10];
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter Array Elements : ");
        for(int i = 0 ; i <arra.length;i++)
        {
            arra[i] = sc.nextInt();
        }

        System.out.println("Printing  Array : ");
        for(int i = 0; i <arra.length;i++)
        {
            System.out.print(arra[i] + " ");
        }

        System.out.println();
        System.out.println("Printing  Reverse Array : ");
        for(int i = arra.length-1; i >=0;i--)
        {
            System.out.print(arra[i] + " ");
        }
    }
}

 public static int[] reverse(int[] array) {

    int j = array.length-1;
    // swap the values at the left and right indices //////
        for(int i=0; i<=j; i++)
        {
             int temp = array[i];
                array[i] = array[j];
                array[j] = temp;
           j--;
        }

         return array;
    }

      public static void main(String []args){
        int[] data = {1,2,3,4,5,6,7,8,9};
        reverse(data);

    }

   import java.util.Scanner;
class ReverseArray 
{
    public static void main(String[] args) 
    {
        int[] arra = new int[10];
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter Array Elements : ");
        for(int i = 0 ; i <arra.length;i++)
        {
            arra[i] = sc.nextInt();
        }

        System.out.println("Printing  Array : ");
        for(int i = 0; i <arra.length;i++)
        {
            System.out.print(arra[i] + " ");
        }

        System.out.println();
        System.out.println("Printing  Reverse Array : ");
        for(int i = arra.length-1; i >=0;i--)
        {
            System.out.print(arra[i] + " ");
        }
    }
}

最有效的方法是向后迭代数组。

我不确定Aaron的解决方案是否调用Collections.reverse(list);有人知道吗?

您的程序只适用于length = 0,1。 你可以试试:

int i = 0, j = validData.length-1 ; 
while(i < j)
{
     swap(validData, i++, j--);  // code for swap not shown, but easy enough
}

2种反转数组的方法。

Using For loop and swap the elements till the mid point with time complexity of O(n/2). private static void reverseArray() { int[] array = new int[] { 1, 2, 3, 4, 5, 6 }; for (int i = 0; i < array.length / 2; i++) { int temp = array[i]; int index = array.length - i - 1; array[i] = array[index]; array[index] = temp; } System.out.println(Arrays.toString(array)); } Using built in function (Collections.reverse()) private static void reverseArrayUsingBuiltInFun() { int[] array = new int[] { 1, 2, 3, 4, 5, 6 }; Collections.reverse(Ints.asList(array)); System.out.println(Arrays.toString(array)); } Output : [6, 5, 4, 3, 2, 1]