Iterative Method

First, we define a function that takes an integer $n as a parameter. Inside the function, we initialize two variables, $f1 and $f2 with 0 and 1 respectively. These represent the first two numbers in the Fibonacci sequence.

Then we use a for loop to calculate the Fibonacci sequence up to the Nth number. The loop starts from 2 because the first two numbers are already initialized. In each iteration, we calculate the next Fibonacci number and update the values of $f1 and $f2 accordingly. The function returns the value of the Nth Fibonacci number, which is stored in the variable $f2.

The Fibonacci sequence is a series of numbers where each number is the sum of the two preceding ones, usually starting with 0 and 1. In this article, we will write a PHP program to find the Nth Fibonacci number.