Write a C program to print Fibonacci series up to n terms using loop. How to generate Fibonacci series up to n terms using loops in C programming. Logic to print Fibonacci series in a given range in C program.

**Example**

**Input**

Input number of terms: 10

**Output**

Fibonacci series: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34

## Required knowledge

Basic C programming, While loop

### What is Fibonacci series?

Fibonacci series is a series of numbers where the current number is the sum of previous two terms. For Example: 0, 1, 1, 2, 3, 5, 8, 13, 21, ... , (n-1th + n-2th)

## Logic to generate Fibonacci series

Below is the step by step descriptive logic to generate n Fibonacci terms.

- Input number of Fibonacci terms from user. Store it in some variable say terms.
- Initialize three variable, I call it as Fibonacci magic initialization. a=0, b=1 and c=0. Here c is the current term, b is the n-1th term and a is n-2th term.
- Run a loop from 1 to terms, incrementing loop counter by 1. The loop structure should look like for(i=1; i<=term; i++). It will iterate through n terms
- Inside the loop copy the value of n-1th to n-2th term i.e. a = b. Second copy the value of nth to n-1th term b = c. Finally compute the new term by adding previous two terms i.e. c = a + b.
- Print the value of c to print the current Fibonacci term.

## Program to print Fibonacci series up to n terms

```
/**
* C program to print Fibonacci series up to n terms
*/
#include <stdio.h>
int main()
{
int a, b, c, i, terms;
/*
* Input a number from user
*/
printf("Enter number of terms: ");
scanf("%d", &terms);
// Fibonacci magic initialization
a = 0;
b = 1;
c = 0;
printf("Fibonacci terms: \n");
// Iterate through n terms
for(i=1; i<=terms; i++)
{
printf("%d, ", c);
a = b; // Copy n-1 to n-2
b = c; // Copy current to n-1
c = a + b; // New term
}
return 0;
}
```

Advance your programming skills by learning this program using recursive approach.

Read more - Program to find nth Fibonacci series using recursion

Output

Enter number of terms: 10 Fibonacci terms: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34,

Before you move on to next exercise or program. Let me show one more example related to Fibonacci series. Let us code the solution to print Fibonacci series between a given range. Below is the program to print Fibonacci series between given range.

## Program to print Fibonacci series in given range

```
/**
* C program to print Fibonacci series in given range
*/
#include <stdio.h>
int main()
{
int a, b, c, start, end;
/*
* Input a number from user
*/
printf("Enter starting term: ");
scanf("%d", &start);
printf("Enter end term: ");
scanf("%d", &end);
// Fibonacci magic initialization
a = 0;
b = 1;
c = 0;
printf("Fibonacci terms: \n");
// Iterate through terms
while(c <= end)
{
// If current term is greater than start term
if(c >= start)
{
printf("%d, ", c);
}
a = b; // Copy n-1 to n-2
b = c; // Copy current to n-1
c = a + b; // New term
}
return 0;
}
```

Output

Enter starting term: 4 Enter end term: 30 Fibonacci terms: 5, 8, 13, 21,

Happy coding 😉

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