This is quite a beginner question but I'm wondering why my do...while loop is not closing.
The program is supposed to loop while the user input is not 'C', 'c', 'F', or 'f'.
It seems to close when just one boolean expression in the while section is valid but not if multiple are valid.
public class CelsToFaren
{
public static void main(String[] args)
{
// scanner setup
Scanner sc = new Scanner(System.in);
// Variable declarations
int celsius;
int answerC;
int farenheit;
int answerF;
char userLetter;
do
{
// initial menu options
System.out.println("Which temperature would you like to convert from? ");
System.out.println(" >(C)elsius ");
System.out.println(" >(F)arenheit ");
// user input of C, c, F, or f to select option
userLetter = sc.next().charAt(0);
// if user input C or c
if ((userLetter == 'C' || userLetter == 'c'))
{
System.out.print("Please enter the temperature: ");
celsius = sc.nextInt();
answerC = ((celsius*9/5)+32);
System.out.println("The answer is: " + answerC + " Farenheit ");
}
else
{
// if user input F or f
if ((userLetter == 'F' || userLetter == 'f'))
{
System.out.print("Please enter the temperature: ");
farenheit = sc.nextInt();
answerF = ((farenheit-32)*5/9);
System.out.println("The answer is: " + answerF + " Celsius ");
}
else
{
// if user input not F, f, C, or c
if ((userLetter != 'F' || userLetter != 'f' || userLetter != 'C' || userLetter != 'c'));
{
System.out.println("Please enter a valid option");
}
}
}
} while ((userLetter != 'c') || (userLetter != 'C') || (userLetter != 'f') || (userLetter != 'F'));
}
}
You need to change the exit logic.
In your case 1 | 0 | 0 = true so the loop continues.
You need to change it to:
while ((userLetter != 'c') && (userLetter != 'C') && (userLetter != 'f') && (userLetter != 'F'));