我被卡住了我想要一个接受整数输入的 while 循环但是被关键字“ABC”打破我做错了什么

【问题标题】：I'm stuck I want a while loop that takes in integer input however is broken by the keyword "ABC" what am I doing wrong我被卡住了我想要一个接受整数输入的 while 循环但是被关键字“ABC”打破我做错了什么
【发布时间】：2022-11-14 13:21:30
【问题描述】：

// defined variables and scanner; ` Scanner sc = new Scanner(System.in); String response = ""; int totalVehicles = 0; int i = 0;

    System.out.println("RIVER BRIDGE SURVEY");

    do{
        System.out.println("How many vehicles are waiting?");
        response = sc.next();

       // if(){}else (this is a remnant of a hopeful past)
        int waitingVehicles = Integer.parseInt(response);

        totalVehicles = totalVehicles + waitingVehicles;
        i = i + 1;

    }
    while(response.equals("ABC") ); // This condition is the problematic bit i think
   `

尝试重新定义变量，取消定义变量，到处都是一些 if 语句，但没有任何效果。也没有错误消息，但循环只运行一次

【问题讨论】：

标签： java loops while-loop do-while

【解决方案1】：

你的 while 循环条件是相反的，你需要一个 not (!)

需要while(!response.equals("ABC"))

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("RIVER BRIDGE SURVEY");
        Scanner sc = new Scanner(System.in); 
        String response = ""; 
        int totalVehicles = 0; int i = 0;
        do{
            System.out.println("How many vehicles are waiting?");
            response = sc.next();

            // if(){}else (this is a remnant of a hopeful past)
            try {
                int waitingVehicles = Integer.parseInt(response);
                totalVehicles = totalVehicles + waitingVehicles;
                i = i + 1;
            } catch (NumberFormatException ex) {
                // error here
            }
                


        }
        while(!response.equals("ABC") ); // Added in !
    }

这将继续运行，直到用户输入ABC

我还在 try { } catch {} 块中添加了应用程序填充获取 NumberFormatException 并无论如何退出循环。

【讨论】：