顺序打印和倒序打印

Question

下面的代码需要将数组中的随机数依次和倒序打印出来。我有逆序打印，但由于某种原因，我似乎无法让它以原始顺序打印。我不确定要修改什么。我目前所打印的“按顺序”打印出一个空白行，“反向顺序”打印出数字。我需要解决什么问题？谢谢！

public class RandomPrintOut
{
   //-----------------------------------------------------------------
   // 
   //-----------------------------------------------------------------
   public static void main (String[] args)
   {

       int numbers[] = new int [10]; 

       for (int i = 0 ; i < 10 ; i++) 
       { 
       numbers [i] = (int) (Math.random () * 100); 
       }



      System.out.println ("The size of the array: " + numbers.length);

      System.out.println ("The numbers in order:");

      for (int index = numbers.length+1; index <= 10; index++)
          System.out.print (numbers[index] + "  ");

      System.out.println ("\nThe numbers in reverse order:");

      for (int index = numbers.length-1; index >= 0; index--)
         System.out.print (numbers[index] + "  ");
   }
}

Answer 1

下面的代码：

for (int index = numbers.length+1; index <= 10; index++)

这里index的初始化值为number.length+1，这个值为10+1=11。 大于 10，因此在这个 for 循环中永远不会满足条件。这就是数组没有按顺序打印的原因。

您需要进行如下更改：

发件人

for (int index = numbers.length+1; index <= 10; index++)
      System.out.print (numbers[index] + "  ");

到

for (int index = 0; index <10; index++)
        System.out.print(numbers[index] + "  ");

修改后的代码如下：

公共类 RandomPrintOut { //------------------------------------------------ ----------------- // //------------------------------------------------ ----------------- 公共静态无效主要（字符串 [] 参数） {

   int numbers[] = new int [10]; 

   for (int i = 0 ; i < 10 ; i++) 
   { 
   numbers [i] = (int) (Math.random () * 100); 
   }

  System.out.println ("The size of the array: " + numbers.length);

  System.out.println ("The numbers in order:");

  for (int index = 0; index < 10; index++)
      System.out.print (numbers[index] + "  ");

  System.out.println ("\nThe numbers in reverse order:");

  for (int index = numbers.length-1; index >= 0; index--)
     System.out.print (numbers[index] + "  ");

} }

在控制台中打印的结果输出：

The size of the array: 10
The numbers in order:
31  50  49  99  29  54  41  16  7  21  
The numbers in reverse order:
21  7  16  41  54  29  99  49  50  31  

Answer 2

仔细查看此循环中index 的值

  for (int index = numbers.length+1; index <= 10; index++)
      System.out.print (numbers[index] + "  ");

尝试手动操作，看看效果如何。这应该可以帮助您识别问题。

Answer 3

public class RandomPrintOut {
   //-----------------------------------------------------------------
   // 
   //-----------------------------------------------------------------
   public static void main (String[] args) {

       int numbers[] = new int [10]; 

       for (int i = 0 ; i < 10 ; i++) { 
       numbers [i] = (int) (Math.random () * 100); 
       }



      System.out.println ("The size of the array: " + numbers.length);

      System.out.println ("The numbers in order:");

      for (int index = 0; index <= numbers.length-1; index++) {
          System.out.print (numbers[index] + "  ");
      }

      System.out.println ("\nThe numbers in reverse order:");

      for (int index = numbers.length-1; index >= 0; index--) {
         System.out.print (numbers[index] + "  ");
      }
   }
}