我想使用两个线程 evenCount 和 oddCount 找到偶数和奇数

Question

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/**
 *
 * @author user
 */



class evenCount extends Thread {
    public void run(){
        for(int i = 2; i >=20; i++)
        {
            try 
            {
                Thread.sleep(500);
            }
            catch(Exception e)
            {
                System.out.println(e);
            }
            System.out.println(i);
        }
    }
}

class oddCount extends Thread {
    
    public void run(){
    for(int i = 21; i>=31; i++)
    {
        try
        {
            Thread.sleep(700);
        }
        
        catch(Exception e)
        {
            System.out.println(e);
        }
        
        System.out.println(i);
    }
    }
}

class mainThread{

    public static void main(String args[]){
        evenCount even = new evenCount();
        oddCount odd  = new oddCount();
        
        even.run();
        odd.run();
    }
}

```````````````````Description````````````````````````

I want to find even and odd numbers but the output show me like this:

Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - Erroneous sym type: Thread. at evenCount.(Thread.java:16) at mainThread.main(Thread.java:56) /Users/user/Library/Caches/NetBeans/8.2/executor-snippets/run.xml:53: Java returned: 1 BUILD FAILED (total time: 0 seconds)

Sometimes it shows build successfull but doesnt show the result(when i use Runnable)

Answer 1

It doesn't show any output, because your for loop condition is wrong.

for(int i = 2; i >=20; i++) and for(int i = 21; i>=31; i++)

both for-loop never get through.

It should be i<=20 and i<=31

At least with above change, you will get output.