while while循环满足2个条件之一

Question

我正在尝试使用do while循环来确定用户是否想要将狗或猫检入Java中的狗窝系统.这个想法是他们在提示时输入"dog"或"cat",任何条目都会导致错误,并且会再次提示他们输入文件名.

如果输入了"cat"或"dog",则会将等效文件分配给程序(dogs.txt或cats.txt),然后系统将运行并将该数据加载到程序中.

以下是当前变量:

private String filename; // holds the name of the file
private Kennel kennel; // holds the kennel
private Scanner scan; // so we can read from keyboard
private String tempFileName;
private String dogsFile = "dogs.txt";
private String catsFile = "cats.txt";

以及导致问题的方法:

private KennelDemo() {
    scan = new Scanner(System.in);

    boolean fileNotCorrect = false;

    System.out.print("Which animal are you looking to check into the kennel?: " + "\n");
    System.out.println("Dog");
    System.out.println("Cat");  
    tempFileName = scan.next();

    do {
        tempFileName.equals("dog");
        filename = dogsFile;
        fileNotCorrect = true;

        /*tempFileName.equals("cat");
        filename = catsFile;
        fileNotCorrect = true;*/
    }
        while(fileNotCorrect = false);
        System.out.println("That is not a valid filename, please enter either 'dog' or 'cat' in lowercase.");

这是运行代码时打印的内容:

**********HELLO***********
Which animal are you looking to check into the kennel?: 
Dog
Cat
cat
That is not a valid filename, please enter either 'dog' or 'cat' in lowercase.
Using file dogs.txt

无论输入什么,它都会为程序分配文件,然后继续加载程序.

我尝试过使用catch {但由于某种原因它不起作用,有人能提供任何帮助吗？

谢谢!

Answer 1

这不是 do-while 的工作方式。你甚至没有检查。

用这个：

 do {
    System.out.print("Which animal are you looking to check into the kennel?: " + "\n");
    System.out.println("Dog");
    System.out.println("Cat");  
    tempFileName = scan.next();
    if(tempFileName.equals("dog") || tempFileName.equals("cat"))
    { 
       filename = tempFileName.equals("dog") ? dogsFile : catsFile;
       fileNotCorrect = true;
    }else{
      System.out.println("That is not a valid filename, please enter either 'dog' or 'cat' in lowercase.");
    }
}
    while(!fileNotCorrect);