Question

我正在尝试为我的编程课程创建一个BART Fare程序。但无论输入如何，我的结果总是-1。为什么我的程序会遵循else if语句？

public static void main(String[] args)
{
    Scanner input = new Scanner(System.in);

    System.out.println("Please enter the ticket type: ");
    String type = input.nextLine();

    System.out.println("Please enter the zone number: ");
    int zone = input.nextInt();

    if ((zone <= 2) && (type == "adult")){
        System.out.println("The fare is 20.");
    }   else if ((zone <= 2) && (type == "child")){
        System.out.println("The fare is 10.5.");
    }   else if ((zone == 3) && (type == "adult")){
        System.out.println("The fare is 30.5.");
    }   else if ((zone == 3) && (type == "child")){
        System.out.println("The fare is 20.");
    }   else if ((zone == 4) && (type == "child")){
        System.out.println("The fare is 20.");
    }   else if ((zone == 4) && (type == "adult")){
        System.out.println("The fare is 43.");
    }   else if ((zone > 4) || (type != "adult") || (type != "child"))
        System.out.println("-1");
    }

}

Answer 1

首先，您的上一个else if错过了＆＃34; {＆＃34;

您的另一个问题是您将两个字符串进行比较的方式。请改用.equals()。

这是一个例子。采取第一个if语句

你有：

if ((zone <= 2) && (type == "adult")){
        System.out.println("The fare is 20.");
    }

尝试：

if ((zone <= 2) && (type.equals("adult"))){
        System.out.println("The fare is 20.");
    }

此比较比较字符串值。对其余的比较执行此操作，您应该看到所需的结果。

为什么我的其他if语句不起作用？

1 个答案: