# C++ program to display Fibonacci series using loop and recursion

In this example, you will learn about C++ program to display Fibonacci series of first n numbers (entered by the user) using the loop and recursion.

Fibonacci Series: It is a series of numbers where the next term in series is the sum of previous two numbers.

`Fibonacci Series: 0 1 1 2 3 5 8 13 ...`

Here is the program to display Fibonacci series in C++.

## Example: C++ program to display Fibonacci series using loop

``````//C++ program to implement Fibonacci series

#include<iostream>
using namespace std;

int main()
{
int oldNum, newNum, fibNum, maxNum;

//Enter maximum number till you want to generate Fibonacci series
cout << "Enter number: ";
cin >> maxNum;

oldNum = 0;
newNum = 1;
fibNum = oldNum + newNum;

cout << "\nFibonacci Series: " << oldNum << " " << newNum;

//while is true till fibNum is less than maxNum and fibNum is calculated
while(fibNum <= maxNum)
{
cout << " " << fibNum;
oldNum = newNum;
newNum = fibNum;
fibNum = oldNum + newNum;
}

cout << "\n";
return 0;
}
``````

Output ## Example: C++ program to display Fibonacci series using recursion

``````//C++ program to display Fibonacci series using recursion

#include<iostream>
using namespace std;

int fibonacci(int n);  //function declaration

int main()
{
int num, fibNum, i;

//Enter the total number in series
cout << "Enter the number of terms: ";
cin >> num;

fibNum = 0;

cout << "\nFibonacci Series: ";

for(i = 1; i <= num; i++)
{
cout << " " <<fibonacci(fibNum); //calling recursive function
fibNum++;
}

cout << "\n";
return 0;
}

//recursive function for Fibonacci series
int fibonacci(int n)
{
if(n == 0)
return 0;
else if (n == 1)
return 1;
else
return(fibonacci(n-1) + fibonacci(n-2)); //calling itself
}
``````

Output Explanation

In this program, we have used recursive function `fibonacci()` to display Fibonacci series.

This program will display `num` number of terms in Fibonacci series.