如何找到随机数组的最小值和最大值，最大值有效，但由于某种原因最小值不

Answer 1

您正在将 smallest 和 largest 初始化为零。在循环之后移动这些初始化和声明。

for (int i = 0; i< intNumbers.length; i = i +1) {
   intNumbers[i] = (int) (Math.random()*100);               
}
int intSmallest = intNumbers[0];
int intLargest = intNumbers[0];    

接下来，我建议Math.max 和Math.min 以及for-each 循环用于第二个循环。喜欢，

for (int val : intNumbers) {
    intLargest = Math.max(intLargest, val);   
    intSmallest = Math.min(intSmallest, val);
}

Answer 2

将 intNumbers 设置为随机值后，需要将 intSmallest 和 intLargest 重新初始化为 intNumbers[0] 以将确切的第一个随机数设置为 anwer 变量。

像这样的东西：

int [] intNumbers = new int [10];//all array elements are 0
    
    int intSmallest = intNumbers[0];///okay here intNumbers[0] is 0
    int intLargest = intNumbers[0];
    
    for (int i = 0; i< intNumbers.length; i = i +1) {
      // here intNumbers[0] gets a new value which can be less than 0
       intNumbers[i] = (int) (Math.random()*100);
       
       //if (intNumbers[i] < intSmallest) intSmallest = intNumbers[i]; 
            
        
    }
     intSmallest = intNumbers[0];// seed the smallest and biggest 
     intLargest = intNumbers[0];//you could also move the decleretion here... 
    jLabel5.setText(Arrays.toString(intNumbers));
     
    for (int i = 0; i< intNumbers.length; i++) {
        
        if (intNumbers[i] > intLargest) {
            intLargest = intNumbers[i];
        }
        if (intNumbers[i] < intSmallest) {
            intSmallest = intNumbers[i];
        }
    }
    
  
    System.out.println(intLargest);
    System.out.println(intSmallest);
}

Answer 3

以下代码有效。 我发现的一件事是 intSmallest 和 intLargest 的初始化。 一开始并不清楚会生成哪些值。 因此，将 intSmallest 设置为区间的最大值，将 intLargest 设置为区间的最小值。 （如果区间的最大值和最小值不明确，则将两者都设置为第一个生成的值，就在生成第一个值之后）。

public class Main
{
    public static void main(String[] args) {
        int [] intNumbers = new int [10];
    
    int intSmallest = 100;
    int intLargest = 0;
    
    for (int i = 0; i< intNumbers.length; i = i +1) {
       intNumbers[i] = (int) (Math.random()*100);
    }

    // edit: better as described above
    intSmallest=intNumbers[0];
    intLargest=intNumbers[0];
    // end of edit

     
    for (int i = 0; i< intNumbers.length; i++) {
        System.out.println("number "+i+" is "+intNumbers[i]);
        if (intNumbers[i] > intLargest) {
            intLargest = intNumbers[i];
        }
        if (intNumbers[i] < intSmallest) {
            intSmallest = intNumbers[i];
        }
    }
    
  
    System.out.println("Largest is "+intLargest);
    System.out.println("Smallest is "+intSmallest);

    }
}

输出：

number 0 is 16
number 1 is 90
number 2 is 41
number 3 is 71
number 4 is 57
number 5 is 5
number 6 is 11
number 7 is 72
number 8 is 32
number 9 is 17
Largest is 90
Smallest is 5

我还想指出，此类问题通常可以通过在各个步骤之间打印值来简单地解决，例如在循环内（而不是仅打印最终结果）。然后你可以看到“某事”出了什么问题。

Answer 4

为什么

intSmallest 被赋值为 0。除非 intNumbers 在循环后包含小于或等于 0 的值，否则 intSmallest 将始终为 0。

如何

方法一：

在循环之后移动 intSmallest 初始化。

    for (int i = 0; i< intNumbers.length; i = i +1) {
       intNumbers[i] = (int) (Math.random()*100);
       
       //if (intNumbers[i] < intSmallest) intSmallest = intNumbers[i]; 
    }

    int intSmallest = intNumbers[0];

方法二：

先排序intNumbers ，最小值为intNumbers[0] ，最大值为intNumbers[intNumbers.length - 1] 。

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    int [] intNumbers = new int [10];
    
    for (int i = 0; i< intNumbers.length; i = i +1) {
       intNumbers[i] = (int) (Math.random()*100);
    }

    jLabel5.setText(Arrays.toString(intNumbers));
     
    Arrays.sort(intNumbers);

    System.out.println(intNumbers[intNumbers.length - 1]); // intLargest
    System.out.println(intNumbers[0]); // intSmallest
}