Question

我正在尝试向我们展示一个很多的迭代器。我一直在收到“休息”的错误。线。它说这是一个无法达成的声明。任何帮助表示赞赏。

public Lot getLot(int number) {
    Lot foundLot = null;
    Iterator it = lots.iterator();
    while (it.hasNext()) {
        Lot b = (Lot) it.next();

        if (b.getNumber() == number) {
            foundLot = b;
            break;
            return foundLot;
        } else {
            System.out.println("lot " + number + " does not exist");
        }
    }
}

Answer 1

你如何期望从一个循环中脱离，然后在打破之后立即返回一些东西？

break;
return foundLot;

Answer 2

它说return foundLot无法访问，因为break语句突破了循环（绕过return）。

Answer 3

它说中断后的行（return foundLot;）是无法访问的语句。

Answer 4

调用return时无法访问break。这是一个不使用break的替代版本：

 public Lot getLot(int number) {  
    Lot foundLot = null;  
    Iterator it=lots.iterator();     
    while(it.hasNext() && foundLot == null) { 
      Lot b=(Lot) it.next();  
      if(b.getNumber() == number) {  
        foundLot = b;  
      }
    }
    if (foundLot == null) {
       System.out.println("lot "+number + " does not exist"); 
    }
    return foundLot;
}

Answer 5

将您的代码更改为：

public Lot getLot(int number)  
{   
    Lot foundLot = null;   
    Iterator it=lots.iterator();      
    while(it.hasNext())  

        {    Lot b=(Lot) it.next();   

    if(b.getNumber() == number) {   
        foundLot = b;   
          break; 
    } 
 else { 
      System.out.println("lot "+number + " does not exist"); 
    } 
   }
 return foundLot;   
}

无法接受的陈述 - 休息;

5 个答案: