# Fibonacci Series in Java

In this tutorial, we will calculate Fibonacci numbers in 3 seperate ways including for loop, do-while loop and arrays. And also we will create a program to find nth Fibonacci number with user input

Fibonacci Series in Java

Also Excel Solution: Calculating Fibonacci Series in Microsoft Excel

Solution 1: Just adding and printing Fibonacci numbers in for array:

``````public class fibonacciNumbers1{

public static void main(String[] args) {

int num1, num2;
num1=1;
num2=1;
System.out.print(num1+" "+num2+" ");

for (int i=1; i<=10; i++) {
num1+=num2;
System.out.print(num1+" ");
num2+=num1;
System.out.print(num2+" ");
}
//1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765 10946 17711
}

}``````

Solution 2: Just adding and printing Fibonacci numbers in do-while array:

``````public class fibonacciNumbers2{

public static void main(String[] args) {

int num1=1, num2=1;

do
{
System.out.print(num1+" "+num2+" ");
num1+=num2;
num2+=num1;
}
while(num1<20000);

//1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765 10946 17711
}

}``````

Solution 3: Keeping Fibonacci values in array (first 25 Fibonacci numbers)

``````public class maxmin {

public static void main(String[] args) {
int[] fibonacciArray = new int[25];
fibonacciArray[0]=1;
fibonacciArray[1]=1;

//calculating fibonacci numbers
for (int i=2; i<fibonacciArray.length; i++)
{
fibonacciArray[i] = fibonacciArray[i-1] + fibonacciArray[i-2];
}

//printing fibonacciArray values
for (int i=0; i<fibonacciArray.length; i++)
{
System.out.print(fibonacciArray[i]+" ");
}
//1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765 10946 17711 28657 46368 75025
}

}``````

Bonus: Finding nth Fibonacci number

``````import java.util.Scanner;

public class maxmin {

public static void main(String[] args) {

Scanner input = new Scanner(System.in);

int[] fibonacciArray = new int[25];
fibonacciArray[0]=1;
fibonacciArray[1]=1;

//calculating fibonacci numbers
for (int i=2; i<fibonacciArray.length; i++)
{
fibonacciArray[i] = fibonacciArray[i-1] + fibonacciArray[i-2];
}

System.out.println("What is n?");
int n=input.nextInt();

System.out.println(n+"th Fibonacci number is:"+fibonacciArray[n-1]);
}

}``````

Output:

What is n?
> 8
8th Fibonacci number is:21