Fibonacci word via recursion in java using string

Question

I have only started writing in java and wrote this program:

public class FibonacciWord{
    public static void main(String[] args){
        if (args.length < 3) System.exit(1);
        int N=Integer.parseInt(args[2]);
        System.out.println(fibonacci(N,args[0],args[1]));
    }
}

public String fibonacci(int N, String a, String b){
    if (N==0) return a;
    return fibonacci(N-1,a+b,a);
}

And then I try to compile it gives a number of errors, the first is:

FibonacciWord.java:9 : error: class, interface, or enum expected 
public String fibonacci(int N, String a, String b){
       ^

What is wrong here?

Answer 1

您在类之外声明方法“ fibonacci”。

Answer 2

Your method is not in a class. It should be like this:

public class FibonacciWord{
    public static void main(String[] args){
        if (args.length < 3) System.exit(1);
        int N=Integer.parseInt(args[2]);
        System.out.println(fibonacci(N,args[0],args[1]));
    }

    public String fibonacci(int N, String a, String b){
        if (N==0) return a;
        return fibonacci(N-1,a+b,a);
    }
}

Answer 3

You should put your method inside the class:

public class FibonacciWord{
    public static void main(String[] args){
        if (args.length < 3) System.exit(1);
        int N=Integer.parseInt(args[2]);
        System.out.println(fibonacci(N,args[0],args[1]));
    }

    public static String fibonacci(int N, String a, String b){
        if (N==0) return a;
        return fibonacci(N-1,a+b,a);
    }
}

And to make it work you should make it static . Or you can create new FibonacciWord object and call this method from it, like so inside main :

FibonacciWord solution = new FibonacciWord();
solution.fibonacci(N,args[0],args[1]);

Answer 4

You method is outside the Main class, place it inside.

You have to make it static in order to call it from the main method.

public class FibonacciWord{

    public static void main(String[] args){
        if (args.length < 3) System.exit(1);
        int N=Integer.parseInt(args[2]);
        System.out.println(fibonacci(N,args[0],args[1]));
    }

    public static String fibonacci(int N, String a, String b){
        if (N==0) return a;
        return fibonacci(N-1,a+b,a);
    }
}