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我有以下代码，稍后我将尝试使用用户在 if/else 语句中输入的输入：

String userGuess = JOptionPane.showInputDialog("The first card is " 
    + firstCard + ". Will the next card be higher, lower or equal?");

如何在此代码所在的 if/else 语句之外使用他们输入的单词，即“更高”、“更低”或“相等”？我需要他们回答的代码是：

if (userGuess == "higher" && nextCard > firstCard)
{
    String userGuess = JOptionPane.showInputDialog(null, "Correct! The current card is a " 
               + nextCard + ". Will the next card be higher, lower or equal?");
    correctGuesses++;
}

编辑：谢谢你的帮助，我想通了！

4

3 回答 3

1

试试这个代码：

if (userGuess.equalsIgnoreCase("higher") && nextCard > firstCard)
{
    String userGuess = JOptionPane.showInputDialog(null, "Correct! The current card is a " 
           + nextCard + ". Will the next card be higher, lower or equal?");
    correctGuesses++;
}

else if (userGuess.equalsIgnoreCase("higher") && nextCard == firstCard)
{
    String userGuess = JOptionPane.showInputDialog(null, "Correct! The current card is a " 
               + nextCard + ". Will the next card be higher, lower or equal?");
    correctGuesses++;
}

else if (userGuess.equalsIgnoreCase("lower") && nextCard < firstCard)
{
    String userGuess = JOptionPane.showInputDialog(null, "Correct! The current card is a " 
               + nextCard + ". Will the next card be higher, lower or equal?");
    correctGuesses++;
}

String不是原始类型。您不能==改用：

if (userGuess.equalsIgnoreCase("higher") && nextCard > firstCard)
{

查看 Oracle关于字符串的文档。这应该会给你进一步的帮助。快乐编码！

于 2013-11-06T20:15:45.737 回答
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如果您userGuess在 if 语句之外声明变量，并在内部分配它，那么您将能够在 if 语句之外使用它。

此外，正如其他地方所述，您应该将字符串与 equals() 进行比较，而不是 ==。

于 2013-11-06T20:14:05.230 回答
0

有两种不错的方法：

  1. 更改变量的名称（因此它不会与现有的 userGuess 变量冲突）并在 if 语句之外声明它。

    String nextGuess = "";
if (userGuess.equals("higher") && nextCard > firstCard) {
    nextGuess = JOptionPane.showInputDialog(null, "Correct! The current card is a " + nextCard + ". Will the next card be higher, lower or equal?");
    correctGuesses++;
}

  2. 每次让用户输入内容时，只需使用相同的 userGuess 变量。

    if (userGuess.equals("higher") && nextCard > firstCard) {
    userGuess = JOptionPane.showInputDialog(null, "Correct! The current card is a " + nextCard + ". Will the next card be higher, lower or equal?");
    correctGuesses++;
}
于 2013-11-06T20:19:02.487 回答