java - 程序不打印除 1 之外的整数

Question

所以我之前在没有方法的情况下编写了这个程序并且它有效。然而，我制定了这些方法，然后事情就停止了。唯一有效的行是打印数组和greaterThanAverage。如果有人想看的话，我将展示原始代码。该程序只为其他所有内容打印 0。

public static void printArray (int n)
{
  int[] arr = new int[n];
  System.out.println("Array on one line: ");
  for(int i = 0; i < arr.length; i++)
  {
     arr[i] = (int) (Math.random() * 500) + 1;
     System.out.print(arr[i] + " ");
  }
}
public static void getMax(int n)
{  
  int[] arr = new int[n];
  int max = arr[0];

  for(int i = 1; i < arr.length; i++)
  {
     if(arr[i] > max)
     {
        max = arr[i];
     }
  }
  System.out.println();
  System.out.println("Maximum: " + max);
}
public static void getMin(int n)
{
  int[] arr = new int[n];
  int min  = arr[0];

  for(int i = 1; i < arr.length; i++)
  {
     if(arr[i] < min)
     {
        min = arr[i];
     }
  }
     System.out.println("Minimum: " + min);
}
public static void getAverage(int n)
{
  double x = 0;
  double y;
  int[] arr = new int[n];
  for(int i = 0; i < arr.length; i ++)
  {
     x = arr[i] + x;
  }
     y = x / arr.length;
    System.out.println("Average: " + y);
}
public static void sumValues(int n)
{
  int sum = 0;
  int[] arr = new int[n];
  for(int num : arr)
  {
     sum = sum + num;
  }
    System.out.println("Sum: " + sum);
}
public static void greaterThanAverage (int n)
{
  int[] arr = new int[n];
  int count = 1;
  double y;
  for(int i = 0; i < arr.length; i ++)
  {
     {         
        count ++;              
     }   
  }       
     System.out.println("Number of integers greater than average: " + count);
}
public static void countInc (int n)
{
  int[] arr = new int[n];
  int count2 = 0;
  for(int i = 0; i < arr.length - 1; i++)
  {       
     if (arr[i] < arr[i + 1])
     {         
        count2++;
     }
  }
     System.out.println("Number of times subsequent value increases: " + count2);
}
public static void countDec (int n)
{
  int[] arr = new int[n];
  int count3 = 0;
  for(int i = 0; i < arr.length - 1; i++)
  {
     if (arr[i] > arr[i + 1])
     {
        count3 ++;
     }
  }
     System.out.println("Number of times  subsequent value decreases: " + count3);
}
public static void printArray3PerLn (int n)
{
  System.out.println("Array with 3 elements per line: ");
  int[] arr = new int[n];
  for(int i = 0; i < arr.length; i++)
  { 
     System.out.print(arr[i]+ " "); 
     if(i % 3 == 2)
     {
        System.out.println();
     }
  }
}
public static void main(String[] args)
{
   Scanner kbd = new Scanner(System.in);
   int sum = 0;
   int n;
   do
   {
     System.out.print("Enter integer n, greater than 0: ");
     n = kbd.nextInt();
     }  while(n < 1);      
     System.out.println();

     printArray(n);

     getMax(n);

     getMin(n);

     sumValues(n);

     getAverage(n);

     greaterThanAverage(n);

     countInc(n);

     countDec(n);

     printArray3PerLn(n);
 }
}

Answer 1

这是因为你没有用数字填充数组

**public static void  countDec (int n)
{
  int[] arr = new int[n]; -<<**

如果你调用该方法的示例计数Dec(5);它将用 0 填充该数组，而不是像您在 printArrayMethod 中那样使用随机数