Java while 循环不支持字符输入检查

Question

下面的代码来自一个游戏，我需要在 java 中生成 2 个随机数，并向用户显示其中一个。然后他们必须猜测第二个数字是高于还是低于第一个。我创建了一个 while 循环来检查输入中的错误，即使条件不成立，循环也会执行。输入 H 表示他们猜测下一个数字更大，L 表示他们认为下一个数字更低

// Input 
System.out.println ("Do you think the second number is higher or lower (enter 'H' or 'L' respectively): ");
char userGuess = Character.toUpperCase(input.next().charAt(0));

// Input error check (and immediate output of second number)
while (userGuess != 'H' || userGuess != 'L') {
    System.out.println ("Sorry, I didn't understand that. Please try again: ");
    userGuess = Character.toUpperCase(input.next().charAt(0));    
}
System.out.println ("The second number was " + secondRandomNumber);

Answer 1

使用 && 而不是 ||。当然不会是H也不会是L

while (userGuess != 'H' && userGuess != 'L') {
    System.out.println ("Sorry, I didn't understand that. Please try again: ");
    userGuess = Character.toUpperCase(input.next().charAt(0));    
}

Java while 循环不支持字符输入检查

Java while loop not working with input checking of characters

java

error-handling

logic

loops

drjava