Fibonacci Series in C

Steven July 06, 2021

The Fibonacci Sequence is the series of numbers following the rule that each number, called a Fibonacci number is equal to the sum of the two preceding numbers.

         0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...

• the 2 found by adding two numbers before it (ie., 1+1).
• the 3 found by adding two numbers before it (ie., 2+1).
• so on...

In this example, you will learn how to display the Fibonacci series in c of first n numbers.

To understand this example, You should have knowledge in

• C Operators
• C for loop
• C while loop and do-while loop
• break and continue statement in C

Fibonacci Series up to n terms

    #include <stdio.h>
    int main() {

      int i, num; //num initialize for number of terms

      // initialize first and second terms
      int a = 0, b = 1;

      // initialize the next term (3rd term)
      int c = a + b;

      printf("Enter the number of terms: ");
      scanf("%d", &num);

      // print the first two terms t1 and t2
      printf("Fibonacci Series: %d, %d, ", a, b);

      // loop starts from 3. because 1 and 2 are already printed
      for (i = 3; i <= num; ++i) {
        printf("%d, ", c);
        a = b;
        b = c;
        c = a + b;
      }
       return 0;
    }

Output

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

0 0

Paul July 06, 2021

    #include<stdio.h>    
    int main(){    
        int num1=0,num2=1,num_next,i,limit;    
        printf("Enter the number of elements:");    
        scanf("%d",&limit);    
        printf("\n%d %d",num1,num2);//printing 0 and 1    
        for(i=2;i<limit;++i){    
           num_next=num1+num2;    
           printf(" %d",num_next);    
           num1=num2;    
           num2=num_next;    
        }  
        return 0;  
     }    

Output

           Enter the number of elements:10

           0 1 1 2 3 5 8 13 21 34

0 0

Andrew July 06, 2021

Fibonacci Series in C using loop

One of the ways to display the Fibonacci series in the C programming language is using for loop.
The program prompts to input the number of terms and displays the series of Fibonacci having the same number of terms.

    #include<stdio.h>
    int main()
    {
        int limit, term_one = 0, term_two = 1, next_term, i;
     
        printf("Enter the number of terms:\n");
        scanf("%d",&limit);
     
        printf("Fibonacci series:\n");
        for ( i = 0 ; i < limit ; i++ )
        {
           if ( i <= 1 )
              next_term = i;
           else
           {
              next_term = term_one + term_two;
              term_one = term_two;
              term_two = next_term;
           }
           printf("%d\n",next_term);
        }
     
        return 0;
    }

Output:

          Enter the number of terms:
          5
          Fibonacci series:
          0
          1
          1
          2
          3

0 0