虽然循环没有取消

Question

我遇到了一个奇怪的问题.

我试图让这个代码循环不断,直到用户输入4; 当用户输入4时,我想使它'Quit_Detect'设置为false.

出于某种原因,它不允许我这样做.代码仍然会循环,直到手动停止.

下面是我用于此程序的所有代码以及一些注释.

import java.util.Scanner;                               // Imports the scanner utility.

public class Start {

    public static void main(String[] args) {
        Scanner Reader = new Scanner(System.in);    // Creates a new scanner.
        @SuppressWarnings("unused")
        boolean Quit_Detect;
        Quit_Detect = true;
        while (Quit_Detect = true)
        {
            int input;                                      // States that input will have a datatype of 'int', or integer. Or, a whole number.
            System.out.println("Please input your option.");
            System.out.println("1. Door with a crack in it");
            System.out.println("2. Normal Wooden Door");
            System.out.println("3. Turn around");
            System.out.println("4. Quit");
            input = Reader.nextInt();                       // Has the user define what the variable 'input' will be set to.
            switch (input)                                  // Uses the Variable 'input' to detect what case to follow.
            {
                case 1:System.out.println("First Option");
                       break;
                case 2:System.out.println("Second Option");
                       break;
                case 3:System.out.println("Third Option");
                       break;
                case 4:Quit_Detect = false;
                       break;
                default:System.out.println("Invalid option.");  //Prints this if the user inputs any number other than 1, 2, or 3.
            }
        }
    }
}

Answer 1

你应该使用:

while (Quit_Detect)

代替:

while (Quit_Detect = true)

第一个语句检查if是否Quit_Detect为true,第二个语句将值设置Quit_Detect为true.