Simple Writing Method of Fibonacci Sequence Realized by php

Fibonacci sequence is a very common class 1 sequence, which is mathematically defined as F0=1, F1=1, Fn=F (n-1) + F (n-2) (n > = 2, n ε N*). In this paper, php is used to simply realize Fibonacci sequence, and the code 10 points is simple and easy to understand, as follows:

<?php 
$arr[1] = 1;
for($i = 2;$i < 100;$i++)
{
    $arr[$i] = $arr[$i-1] + $arr[$i-2];
}
echo join(",",$arr);// Combine arrays into 1 String output 
?>

So far, the display output of Fibonacci sequence of n within 100 in Fn=F (n-1) + F (n-2) is realized.