In this C++ tutorial, you will learn how to write a C++ program to generate Fibonacci series, and print them. We will cover programs to generate Fibonacci series using While loop, Do-while loop, and For loop.

## C++ Fibonacci Series

Fibonacci Series is a series in which the current element is equal to the sum of two immediate previous elements. Fibonacci series start with 0 and 1, and progresses.

### Algorithm to Generate Fibonacci Series

You can use following algorithm to generate a Fibonacci Series using looping technique.

1. Start.
2. Take a variable `n`. We have to generate `n` items of Fibonacci series.
3. Create an Array `fibo[]` with the size of `n`.
4. Take `index` with initial value of zero.
5. Check if `index` is less than `n`. If false go to step 11.
6. If index is `0`, assign fib[index] with `0`. Go to step 9.
7. If index is `1`, assign fib[index] with `1`. Go to step 9.
8. Assign `fibo[index]` with the sum of previous two elements `fibo[index-1]` and `fibo[index-2]`.
9. Increment `index`. Go to step 5.
10. Print `fibo[]`.
11. Stop.

## Fibonacci Series using While loop

In the following program, we shall use C++ While Loop to generate Fibonacci Series.

C++ Program

```#include <iostream>
using namespace std;

int main() {
int n = 10;
int fibo[n];

//generate fibonacci series
int index = 0;
while (index < n) {
if (index == 0)
fibo[index] = 0;
else if (index == 1)
fibo[index] = 1;
else
fibo[index] = fibo[index - 1] + fibo[index - 2];

index++;
}

//print fibonacci series
for (int i = 0; i < n; i++)
cout << fibo[i] << "  ";
}```

Output

`0  1  1  2  3  5  8  13  21  34`

## Fibonacci Series using Do-while loop

In the following program, we shall use C++ Do-while Loop to generate Fibonacci Series.

C++ Program

```#include <iostream>
using namespace std;

int main() {
int n = 15;
int fibo[n];

//generate fibonacci series
int index = 0;

do {
if (index == 0)
fibo[index] = 0;
else if (index == 1)
fibo[index] = 1;
else
fibo[index] = fibo[index - 1] + fibo[index - 2];

index++;
} while (index < n);

//print fibonacci series
for (int i = 0; i < n; i++)
cout << fibo[i] << "  ";
}```

Output

`0  1  1  2  3  5  8  13  21  34  55  89  144  233  377`

## Fibonacci Series using For loop

In the following program, we shall use C++ For Loop to generate Fibonacci Series.

C++ Program

```#include <iostream>
using namespace std;

int main() {
int n = 10;
int fibo[n];

//generate fibonacci series
for (int index = 0; index < n; index++) {
if (index == 0)
fibo[index] = 0;
else if (index == 1)
fibo[index] = 1;
else
fibo[index] = fibo[index - 1] + fibo[index - 2];
}

//print fibonacci series
for (int i = 0; i < n; i++)
cout << fibo[i] << "  ";
}```

Output

`0  1  1  2  3  5  8  13  21  34`

## Conclusion

In this C++ Tutorial, we learned how to generate a Fibonacci series using looping techniques in C++.