如果用户键入QUIT，则退出While循环

Question

I'm writing a spellchecker program that will ask the user for a word and will compare it to a list of words in an array that I have made.

This program needs to be never ending until the user types quit .

So my question is, what would I put while(>> here <<) that would end the program as soon as the user types quit instead of typing another word. The word quit is not in the array.

Here is my code for the while loop so far (not done yet, but it bugs me when I test this and the loop doesn't end on quit, so that's what I need done first).

String quit = "quit"; 
//this is only declared as "quit" to get the loop to run for testing

while(quit.equals("quit")) {

    System.out.println("Please every a word or QUIT to exit");
    String guess = input.nextLine();

    for(int i = 0; i < words.length; i++) {

        if(guess.equals(words[i])) {

            System.out.println("That word is spelled correctly.");
        }   

        else {

            System.out.println("That word is not spelled correctly.");
            System.out.println("Would you like to add it to the dictionary? (Y/N)");
        }
    }   
}

If you suggest another way of doing it that's not a while loop, although I appreciate it, it has to be a while loop for school purposes.

Answer 1

Your condition is always true. If you want to react to a user typing in "quit" while entering a new guess, you can do it with an infinite loop and a break , like this:

while (true) {
    System.out.println("Please every a word or QUIT to exit");
    String guess = input.nextLine();
    if (quit.equalsIgnoreCase(guess)) {
        break;
    }
    for(int i = 0; i < words.length; i++) {
        ...
    }
}

Answer 2

Use Do-While loop instead of simple While loop.

The code looks like this:

String quit = "quit"; 
//this is only declared as "quit" to get the loop to run for testing

    do {

        System.out.println("Please every a word or QUIT to exit");
        String guess = input.nextLine();

        for(int i = 0; i < words.length; i++) {

            if(guess.equals(words[i])) {

                System.out.println("That word is spelled correctly.");
            }   

            else {

                System.out.println("That word is not spelled correctly.");
                System.out.println("Would you like to add it to the dictionary? (Y/N)");
            }
        }   
    }

    while(!quit.equals("quit"));

Answer 3

Your loop while will keep going until you change your String quit to something other than "quit". Here is an example:

while(quit.equals("quit")) {

    System.out.println("Please every a word or QUIT to exit");
    String guess = input.nextLine();

    for(int i = 0; i < words.length; i++) 
    {

        if(guess.equals(words[i])) 
        {
            System.out.println("That word is spelled correctly.");
        } 
        if(guess.equals("quit") {
            quit = "something_else";
        }  
        else
        {
            System.out.println("That word is not spelled correctly.");
            System.out.println("Would you like to add it to the dictionary? (Y/N)");
        }
}   
}

Answer 4

If you must quit right after input, and you must use a while condition to trigger it, then your input has to be at the end of the loop so that the condition is checked right after the input is entered. You could do that like this:

System.out.println("Please enter a word or QUIT to exit");
String guess = input.nextLine();

while (!guess.equalsIgnoreCase("quit")) {
    for(int i = 0; i < words.length; i++) {
        if(guess.equals(words[i])) {
            System.out.println("That word is spelled correctly.");
        } else {
            System.out.println("That word is not spelled correctly.");
            System.out.println("Would you like to add it to the dictionary? (Y/N)");
        }
    }
    System.out.println("Please enter a word or QUIT to exit");
    String guess = input.nextLine();
}

Answer 5

Use the below Condition :

if(StringUtils.equalsIgnoreCase(guess,"QUIT"))  {
    System.out.println("Quitting the loop");
    return
}

Answer 6

My wrong, it will work better with "!="

"quit.compareTo(guess)!=0" in your while