如何在方法之间传递参数并使用Java正确调用方法？

Question

该方案应做到以下几点：

public class UnitSixInClassFall2018 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        UnitSixInClassFall2018 u = new UnitSixInClassFall2018();
        u.getHeartRate();
        System.out.println();
        Scanner scan = new Scanner(System.in);
        u.checkHeartRate(0);
        // END MAIN
    }

    public int getHeartRate(){
        System.out.print("Please enter your heart rate: ");
        Scanner scan = new Scanner(System.in);
        int heartRate = scan.nextInt();
        return 0;
    }

    public void checkHeartRate(int heartRate){
        if (heartRate > 100) {
           String result = "High";
        }
        else if (heartRate < 60) {
           String result = "Low";
        }
        else {
           String result = "Normal";
        }
    }

    public String printHRResults(String result) {  
       System.out.print("Your hear rate is " + result + ".");
       return result; 
    }

}

当这是运行时，所有的输出是“请输入你的心率：”。一旦我输入一个整数，程序就结束了。做错了什么？

Answer 1

你应该改变这个方法，像这样返回心率：

public int getHeartRate(){
    System.out.print("Please enter your heart rate: ");
    Scanner scan = new Scanner(System.in);
    int heartRate = scan.nextInt();
    // Also add this
    scan.close();
    return heartRate;
}

并更改此方法以返回结果：

public String checkHeartRate(int heartRate){
    if (heartRate > 100) {
       return "High";
    }
    else if (heartRate < 60) {
       return "Low";
    }
    else {
       return "Normal";
    }

}

然后在您的主要方法中：

// get the heart rate
int heartRate = u.getHeartRate();
// Call the checkHeartRate method
String result = checkHeartRate(heartRate);
// call the printHRResults 
printHRResults(result);

那应该能解决你的问题。