Question

The Fibonacci sequence begins with 0 and then 1 follows. All subsequent values are the sum of the previous two, for example: 0, 1, 1, 2, 3, 5, 8, 13. Complete the fibonacci() method, which takes in an index, n, and returns the nth value in the sequence. Any negative index values should return -1.
Ex: If the input is: 7
the out put is :fibonacci(7) is 13

import java.util.Scanner;
public class LabProgram {
public static int fibonacci(int n) {
/* Type your code here. */
public static void main(String[] args) {
Scanner scnr = new Scanner(System.in);
int startNum;
System.out.println("Enter your number: ");
startNum = scnr.nextInt();
System.out.println("fibonnaci(" + startNum + ") is " + fibonacci(startNum));
}
}

Answer 1

You could use recursion to write java method for computing fibonacci numbers. Though it will be inefficient for n > about 50, it will work.

public static int fibonacci(int n) {

if (n < 0) { return -1; }

if (n < 2) { return n; }

else { return fibonacci(n-1)+fibonacci(n-2); }

}

Hope this helps.