Fibonacci Series Program in PHP
In this post, you will learn different ways to write the Fibonacci series of programs using the PHP programming language.
The Fibonacci series is the sequence of numbers in which the next number is the sum of the previous two numbers. The Fibonacci series was well-known hundreds of years earlier. The "Fibonacci" name came from the nickname "Bonacci".
We can easily remember Fibonacci Sequence using the Fibonacci Day, which is November 23rd. As 23rd November has the digits "1, 1, 2, 3" which is part of the sequence.
In the above image, the first two numbers are 0 and 1. So, according to the Fibonacci rule, the third number is 1 (sum of 0 and 1). The fourth number is 2, and so on.
0 + 1 = 1 // 0, 1, 1
1 + 1 = 2 // 0, 1, 1, 2
1 + 2 = 3 // 0, 1, 1, 2, 3
2 + 3 = 5 // 0, 1, 1, 2, 3, 50 ,1 , 1, 2, 3, 5, 8, 13, 21, 34....
Fibonacci Series Program in PHP using For Loop
Here, you will learn how to print the Fibonacci series using a for loop in PHP. In this below code, $f1 contains the first number, i.e., 0, and $f2 contains the second number, i.e., 1 and $n contains 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 of the above code
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
Fibonacci Series Program in PHP using while loop
In the given PHP program, we have used the while loop to print the Fibonacci series upto 15 in PHP. First, we print the first and second numbers. Then we use the while loop where we get the next number by adding the previous two numbers and simultaneously we swap the first number with the second and the second with the third.
<?php
$n = 0;
$a = 0;
$b = 2;
echo "Fibonacci series upto 15 : ";
echo "$a, $b";
while ($n < 16 )
{
$c = $b + $a;
echo ", ";
echo "$c";
$a = $b;
$b = $c;
$n = $n + 1;
}
?> Fibonacci series upto 15 : 0, 2, 2, 4, 6, 10, 16, 26, 42, 68, 110, 178, 288, 466, 754, 1220, 1974, 3194 Fibonacci Series Program in PHP using Recursive Function
Recursion function is a function that is called by itself. In the given example, we call the recursion function to get the Fibonacci series. A recursion function continues until some condition is met to prevent it. That's why we use the if else statement to break the infinite recursion.
<?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 of the above code
Fibonacci series upto 20 -
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377Fibonacci Series Program in PHP using the iterative way
In the given example, we print the first and second numbers. And then we send the flow to the iterative while loop where we get the next number by adding the previous two numbers and, simultaneously, we swap the first number with the second and the second with the third. So that we print the Fibonacci series.
<?php
function Fibonacci($n){
$num1 = 0;
$num2 = 1;
$counter = 0;
while ($counter < $n){
echo ' '.$num1;
$num3 = $num2 + $num1;
$num1 = $num2;
$num2 = $num3;
$counter = $counter + 1;
}
}
// Driver Code
$n = 12;
Fibonacci($n);
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