以下代码的表达式开头错误（需要帮助调试）

Question

我为Java编程类简介创建了一个用两个数字表示的方法调用程序的GCD。基本上，用户输入两个数字，然后将这些数字发送到我创建的“ gcd”方法，然后它计算这两个数字的GCD，并显示给用户。对于以下代码行，我得到了“非法代码开始”：System.out.println（“ GCD为：” + gcd +）;我在下面放置了我的Java代码以供参考，以及有关调试它的帮助，我不确定自己做错了..谢谢！

package gcdfunction;

/**
*
* @
*/

import java.util.Scanner;

public class GcdFunction {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {

    //initializing variables
    Scanner input = new Scanner(System.in);
    int num1;
    int num2;

    //Asking user for first number
    System.out.print("Enter the first number: ");

    //Prompting user input for first number
    num1=input.nextInt();

    //Asking user for second number
    System.out.print("Enter the second number: ");

    //Prompting user input for secoond number
    num2=input.nextInt();

    //calling GCD Method
    int gcd = gcd(num1,num2);

    //The GCD of the two numbers the user chose displayed to the user
    System.out.println("The GCD is: " + gcd +);
}

//GCD Function
public static int gcd(int x, int y){

    int num1 = 0;
    int num2 = 0;

    while(num1 != num2){
        while(num1>num2){
            num1 = num1 - num2;
        }
        while(num2 > num1){
            num2 = num2 - num1;
        }
    }

    return num1;

}
}

Answer 1

删除main中最后一个println语句中gcd之后的+符号。您的方法gcd也不正确，将始终返回0，因为num1和num2在进入while循环之前被设置为零。我只是将gcd的方法参数名称设置为num1和num2。那会给你你的gcd。我还删除了内部循环，因为您不需要GCD算法的内部循环。

package gcdfunction;

import java.util.Scanner;

public class GcdFunction {

    public static void main(String[] args) {

        //initializing variables
        Scanner input = new Scanner(System.in);
        int num1;
        int num2;

        //Asking user for first number
        System.out.print("Enter the first number: ");

        //Prompting user input for first number
        num1=input.nextInt();

        //Asking user for second number
        System.out.print("Enter the second number: ");

        //Prompting user input for secoond number
        num2=input.nextInt();

        //calling GCD Method
        int gcd = gcd(num1,num2);

        //The GCD of the two numbers the user chose displayed to the user
        System.out.println("The GCD is: " + gcd);
    }

    //GCD Function
    public static int gcd(int num1, int num2){
        while(num1 != num2){
            if (num1 > num2){
                num1 = num1 - num2;
            }
            else {
                num2 = num2 - num1;
            }
        }

        return num1;

    }
}