如何使用方法？

Question

我是爪哇的初学者。在我的程序中，我编写了一个代码，用于随机n个数组，偶数索引，奇数元素，反转元素，数组的第一个，最后一个元素。但是现在我想使用单独的方法来实现我的程序。我该怎么做？

那?

public class Rand {

        public static void main(String[] args) {
            // TODO Auto-generated method stub
            Scanner input = new Scanner (System.in);
             System.out.print("Enter the number of values:");

              int[] values = new int[input.nextInt()];
              Random rand = new Random();
              for (int i = 0; i < values.length; i++) {
                int n = rand.nextInt(20);
                values[i] = n;
              }
              System.out.print("Array: ");
              for (int i = 0; i < values.length; i++) {
                  System.out.print( " " + values[i]);
                }

              System.out.println();
              System.out.print("Even index: ");
              for (int i = 0; i < values.length; i++) {
                    if (i % 2 == 0) {
                        System.out.print( " " +values[i]);
                    }
              }
              System.out.println();
              System.out.print("Odd element:");
                for (int i = 0; i < values.length; i++) {
                    if (values[i] % 2 != 0) {
                        System.out.print(" " + values[i]);
                    }
                }
                System.out.println();
                System.out.print("Reverse order:");
                for (int i = values.length - 1; i > -1; i--) {
                    System.out.print( " "+ values[i]);
                }
                System.out.println();
                System.out.print("First, middle and last element:");
                System.out.print(" " + values[0]);

                if (values.length %2 ==0)
                {
                  System.out.print(" " + values[(values.length /2)-1]);
                  System.out.print(" " + values[values.length /2]);

                }
                System.out.print( " " + values[values.length - 1]);



        }

    }

Answer 1

举个例子，你可以在你的main中替换这个代码

         Scanner input = new Scanner (System.in);
         System.out.print("Enter the number of values:");

          int[] values = new int[input.nextInt()];
          Random rand = new Random();
          for (int i = 0; i < values.length; i++) {
            int n = rand.nextInt(20);
            values[i] = n;
          }

使用

         int[] values = getValues ();

getValues看起来像什么

private static int [] getValues () {
     Scanner input = new Scanner (System.in);
     System.out.print("Enter the number of values:");

      int[] values = new int[input.nextInt()];
      Random rand = new Random();
      for (int i = 0; i < values.length; i++) {
        int n = rand.nextInt(20);
        values[i] = n;
      }

      // lets also close the Scanner
      input.close ();
      return values;