Question

这是我的代码。当我使用bluej进行编译时，它会突出显示最后一个}并且说缺少return语句。我不能放空，因为它是一个布尔值。有任何想法吗？

 public boolean runAJob() {
     boolean jobsFinished = false;
     Job firstJob = getCurrentJob();
     String jobName = firstJob.getName();
     int jobDuration = firstJob.getDuration();
     if (!myJob.isEmpty()&& jobDuration > 0 && jobDuration <= myTotalDuration) { 
         myTotalDuration -= jobDuration;
         myFinishedJobs.add(myJob.get(0));
         myJob.remove(0);
         System.out.println("'"+jobName+"'" +" is completed. "+ myTotalDuration+ " seconds remaining on the clock");
         jobsFinished = true;
    } else {
          System.out.println("JobQueue is empty");
    }
}

Answer 1

在Java中，与在类C语言中一样，需要基于方法/函数的返回类型的return语句。

在你的情况下：

public boolean runAJob() { ... }

要求返回布尔值。 因此，当您尝试编译代码，并且方法体中没有return语句时，编译器会抱怨。

所以，你要做的是确定你想要返回什么信息（在这种情况下是一个布尔值）。正如其他人所指出的那样，你应该返回 jobsFinished，因为这是一个布尔类型，你希望在方法调用时确定它的值。

 public boolean runAJob()
    {
        boolean jobsFinished = false;
        Job firstJob = getCurrentJob();
        String jobName = firstJob.getName();
        int jobDuration = firstJob.getDuration();
        if (!myJob.isEmpty()&& jobDuration > 0 && jobDuration <= myTotalDuration)
        { 
             myTotalDuration -= jobDuration;
             myFinishedJobs.add(myJob.get(0));
             myJob.remove(0);
             System.out.println("'"+jobName+"'" +" is completed. "+ myTotalDuration+ " seconds remaining on the clock");
             jobsFinished = true;
             return jobsFinished; //this is one possible place

        }
        else
        {
            System.out.println("JobQueue is empty");
        }
        //here is another possible place where you could have put the return
        //return jobsFinished;
    }

Answer 2

你应该简单地返回jobsFinished。

要明确：

public boolean runAJob()
        {
            boolean jobsFinished = false;
            Job firstJob = getCurrentJob();
            String jobName = firstJob.getName();
            int jobDuration = firstJob.getDuration();
            if (!myJob.isEmpty()&& jobDuration > 0 && jobDuration <= myTotalDuration)
            { 
                 myTotalDuration -= jobDuration;
                 myFinishedJobs.add(myJob.get(0));
                 myJob.remove(0);
                 System.out.println("'"+jobName+"'" +" is completed. "+ myTotalDuration+ " seconds remaining on the clock");
                 jobsFinished = true;
            }
            else
            {
                System.out.println("JobQueue is empty");
            }
            return jobsFinished;
        }

Answer 3

return语句必须始终是方法中的最后一个语句

public boolean runAJob()
    {
        boolean jobsFinished = false;

        Job firstJob = getCurrentJob();

        String jobName = firstJob.getName();

        int jobDuration = firstJob.getDuration();

        if (!myJob.isEmpty()&& jobDuration > 0 && jobDuration <= myTotalDuration)

        { 

             myTotalDuration -= jobDuration;

             myFinishedJobs.add(myJob.get(0));

             myJob.remove(0);

             System.out.println("'"+jobName+"'" +" is completed. "+ myTotalDuration+ "

时钟剩余时间“）;

             jobsFinished = true;

        }

        else

        {

            System.out.println("JobQueue is empty");

        }

        return jobsFinished;
    }

Answer 4

你只是忘了放返回工作完成; 在System.out.print行结束之后。当你这样做时，它应该成功运行和编译，我确信这是因为我今天犯了同样的错误：P

祝你好运。

-Keelen

Answer 5

更改您的功能定义/原型...使用此public void runAJob()代替您使用的内容...

将boolean替换为原型中的void ..然后尝试

Answer 6

您指定了boolean返回类型，但您的功能并未返回任何值。

jobsFinished变量是多余的，您的else分支也是如此：

public boolean runAJob() {
    Job firstJob = getCurrentJob();    
    int jobDuration = firstJob.getDuration();

    if (!myJob.isEmpty() && jobDuration > 0 && jobDuration <= myTotalDuration) { 
        String jobName = firstJob.getName();
        myTotalDuration -= jobDuration;
        myFinishedJobs.add(myJob.get(0));
        myJob.remove(0);
        System.out.println("'"+jobName+"'" +" is completed. "+ myTotalDuration+ " seconds remaining on the clock");
        return true;
    } 

    System.out.println("JobQueue is empty");
    return false;
}

如果满足条件，函数将在最后两个语句之前return，因此else是不必要的。我还将String jobName = firstJob.getName();移到了if分支内，因为您没有使用它。

如果您希望在函数末尾使用boolean变量和return变量，那么您可以这样做：

public boolean runAJob() {
    Job firstJob = getCurrentJob();    
    int jobDuration = firstJob.getDuration();
    boolean jobsFinished = !myJob.isEmpty() && jobDuration > 0 && jobDuration <= myTotalDuration;
    if (jobsFinished) { 
        String jobName = firstJob.getName();
        myTotalDuration -= jobDuration;
        myFinishedJobs.add(myJob.get(0));
        myJob.remove(0);
        System.out.println("'"+jobName+"'" +" is completed. "+ myTotalDuration+ " seconds remaining on the clock");            
    } 
    else {
        System.out.println("JobQueue is empty");
    }   
    return jobsFinished;
}

缺少退货声明？

6 个答案: