# Fibonacci Series Program in PHP

## What is Fibonacci Series

The Fibonacci sequence is a collection of numbers that begins with a one or a zero, succeeded by a one, and proceeds based on the specific rule that each number is called a Fibonacci number. This number is equivalent to the sum of the preceding two numbers.

If it indicates the Fibonacci sequence F (n), where n is the first term in the sequence, the following equation gets for n = 0, where the first two terms are determined as 0 and 1 by convention:

F (0) = 0, 1, 1, 2, 3, 5, 8, 13, 21, 35…..

## Fibonacci Series up to n Terms

Below is the example of C program

#include <stdio.h>

int main() {

int i, n, t1 = 0, t2 = 1, nextTerm;

printf(“Enter the number of terms: “);

scanf(“%d”, &n);

printf(“Fibonacci Series: “);

for (i = 1; i <= n; ++i) {

printf(“%d, “, t1);

nextTerm = t1 + t2;

t1 = t2;

t2 = nextTerm;

}

return 0;

}

## Fibonacci Series Program in PHP

For understanding the pattern of the Fibonacci series, below are the basic examples of the sample code snippet:

Example1

The basic concept to find the Fibonacci series is;

In this, printFibonacci function has the logic of the Fibonacci series, which adds two previous digits and gets the subsequent term.

<?php

function printFibonacci(\$n)

{

\$first = 0;

\$second = 1;

echo “Fibonacci Series \n”;

echo \$first.’ ‘.\$second.’ ‘;

for(\$i = 2; \$i < \$n; \$i++){

\$third = \$first + \$second;

echo \$third.’ ‘;

\$first = \$second;

\$second = \$third;

}

}

printFibonacci(6);

?>

Output

Fibonacci Series 0 1 1 2 3 5

Example 2

In this example, we will create the PHP program to print the Fibonacci Series.

Here we have the logic of if numbers in a series are the sum to their preceding two numbers, then we can consider it as a Fibonacci series.

<?php

\$num = 0;

\$n1 = 0;

\$n2 = 1;

echo “<h3> This Fibonacci series for first 12 numbers: </h3>”;

echo “\n”;

echo \$n1.’ ‘.\$n2.’ ‘;

while (\$num < 10 )

{

\$n3 = \$n2 + \$n1;

echo \$n3.’ ‘;

\$n1 = \$n2;

\$n2 = \$n3;

\$num = \$num + 1;

}

?>

Output

This Fibonacci series for first 12 numbers:

0 1 1 2 3 5 8 13 21 34 55 89

Example 3

Fibonacci Series Program using For Loop logic Here,

In this example: we are printing the Fibonacci series using for loop in PHP.

In this below code snippet, \$f1 comprises the first number,

“0” and \$f2 comprises the second number, “1” and \$n comprise the total Fibonacci series number count.

<?php

\$f1 = 0;

\$f2 = 1;

\$n = 30;

echo \$f1;

echo ‘<br/>’;

echo \$f2;

for(\$i = 1; \$i <= \$n; \$i++) {

\$f3 = \$f1 + \$f2;

\$f1 = \$f2;

\$f2 = \$f3;

echo \$f3 .”<br />”;

}

?>

Output

0

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

121393

196418

317811

514229

832040

1346269

Example: 4

Fibonacci Series Program using Recursive Function

Here we have the “Recursion function”, which we can consider as a method.

<?php

echo “<h2>Fibonacci series upto 20 – </h2>”;

echo “\n\n”;

\$n = 15;

/* Recursive function  */

function recursive(\$n){

if(\$n == 0){

return 0;

}

else if( \$n == 1)

{

return 1;

}

else {

return (recursive(\$n-1) + recursive(\$n-2));

}

}

/* Call Function */

for (\$i = 0; \$i < \$n; \$i++){

echo recursive(\$i);

echo “\n”;

}

?>

Output

Fibonacci series up to 20 –

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

Example: 5

Without Using Recursion Function

<?php

\$n = 0;

\$a = 0;

\$b = 2;

echo “Fibonacci series with the first 2 numbers as 0 and 2 is: “;

echo “\$a, \$b”;

while (\$n < 26 )

{

\$c = \$b + \$a;

echo “, “;

echo “\$c”;

\$a = \$b;

\$b = \$c;

\$n = \$n + 1;

}

?>

Output

Fibonacci series with the first 2 numbers as 0 and 2 is:

0, 2, 2, 4, 6, 10, 16, 26, 42, 68, 110, 178, 288, 466, 754, 1220, 1974, 3194, 5168, 8362, 13530, 21892, 35422, 57314, 92736, 150050, 242786, 392836

Checkout: Polymorphism in PHP

## Conclusion

We hope this article helped you with the understanding of the Fibonacci Series Program in Java.

If you’re interested to learn more about full-stack software development, check out upGrad & IIIT-B’s PG Diploma in Full-stack Software Development which is designed for working professionals and offers 500+ hours of rigorous training, 9+ projects, and assignments, IIIT-B Alumni status, practical hands-on capstone projects & job assistance with top firms.

## Become a Full Stack Developer

UPGRAD AND IIIT-BANGALORE'S PG DIPLOMA IN FULL STACK SOFTWARE DEVELOPMENT 