How to do Fibonacci sequence in php

Fibonacci sequence, also known as the golden section sequence, was named after the mathematician Leonardoda Fibonacci used rabbit reproduction as an example. It is introduced, so it is also called the "Rabbit Sequence", which refers to such a sequence: 1, 1, 2, 3, 5, 8, 13, 21, 34,..., simply put, the Fibonacci Sequence is Series elements, the first two elements are added to get the next element, starting from 0 and 1.

How to implement Fibonacci sequence in PHP?

In this article, we will introduce to you how to implement the Fibonacci sequence with PHP. Given a number n, we need to find the Fibonacci sequence up to the nth term.

Example:

输入：10
输出：0 1 1 2 3 5 8 13 21 34
输入：15
输出：0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

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Method 1: Use recursion

Recursion is how we call the same function repeatedly until a basic condition is matched to end the recursion.

<?php
function Fibonacci($number){
 
    if ($number == 0)
        return 0;
    else if ($number == 1)
        return 1;
    else
        return (Fibonacci($number-1) +
            Fibonacci($number-2));
}
$number = 10;
for ($counter = 0; $counter < $number; $counter++){
    echo Fibonacci($counter),&#39; &#39;;
}

Output:

0 1 1 2 3 5 8 13 21 34

Method 2: Using iterative method

First, we initialize the first and second numbers to 0 and 1. Then, we print the first and second numbers. Then we send the process to the iterative while loop where we get the next number by adding the previous two numbers, at the same time we swap the first number with the second number and the second number with the third number.

<?php
function Fibonacci($n){
 
    $num1 = 0;
    $num2 = 1;
 
    $counter = 0;
    while ($counter < $n){
        echo &#39; &#39;.$num1;
        $num3 = $num2 + $num1;
        $num1 = $num2;
        $num2 = $num3;
        $counter = $counter + 1;
    }
}
 
$n = 10;
Fibonacci($n);

Output:

0 1 1 2 3 5 8 13 21 34

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