java - 如何用用户输入的字符串结束 do while 循环？

Question

public static void main (String[] args)
    {
        do {
            Scanner keyboard = new Scanner(System.in);
            System.out.print("Enter a string: ");
            String sentence = keyboard.nextLine();

            System.out.print("Enter a letter: ");
            String fullLetter = keyboard.nextLine();
            char letter = fullLetter.charAt(0);
            keyboard.nextLine();

            int amount = 0;
            for (int i = 0; i < sentence.length(); i++) {
                char ch = sentence.charAt(i);
                if (ch == letter) {
                    amount++;
                }
            }

            System.out.println(letter + " appears " + amount + " times in " + sentence);

            System.out.print("Continue? ");
            String decide = keyboard.nextLine();
        } while (decide.equals("yes"));
    }

}

我希望用户在循环结束时输入"is"或“否”，然后我希望该输入确定程序是否会再次循环。就目前而言，我的代码的最后一行不起作用。我环顾四周，不确定应该做什么来解决这个问题。

Answer 1

您需要在循环外部声明变量decide并在内部初始化:

String decide;
do {
    //do something ...
    decide = keyboard.nextLine();
} while (decide.equals("yes"));