Comparison between static and instance method in PHP

<?php

// PHP code for static method 
class College
{
    // Static function
    static function getCollegeName()
    {
            return "MNNIT Allahabad";
    }
}

// Calling function without its object
echo (College::getCollegeName());
?>

<?php
// Program for instance methods

class College
{
    // This data can not be accessed
    // from outside of the class
    private $name;
    
    // This function sets the name
    function setName($name) {
        $this -> name = $name;
    }
    
    // This function return name
    function getName() {
        return $this -> name;
    }
}

// Creating an object of type College
$obj = new College;

// Setting name
$obj -> setName("Geeks");

// Getting name
echo ($obj -> getName());
?>

<?php

// Program to compare execution time 
// of static and instance methods
set_time_limit(0);

// Checking php version
echo 'Current PHP version: ' . phpversion();

// Creating class for static
Class St {

    public static $count = 0;
    
    // function that will print nothing
    public static function getResult()
    {
        self::$count = self::$count + 1;
    }
}

// For calculating time
$time_start_static = microtime(true);

// This loop will run 100000 times
for($i = 0; $i < 100000; $i++) {
    St::getResult();
}

// Execution time for static method ends here
$time_end_static = microtime(true);

// Execution time is end -start time
$time_static = $time_end_static - $time_start_static;

// Printing the result
echo "\nTotal execution time is for static method is: '$time_static'";

// Demo class for instance method
class Ins {
    private $count = 0;
    
    // Function that will not print anything
    public function getResult() {
        $this -> count = $this -> count + 2;
    }
}

// Creating an instance object
$ob = new Ins;

// Starting time is initialize
$time_start_instance = microtime(true);

// For time loop is run
for($i = 0; $i < 100000; $i++)
{
    $ob -> getResult();
}

// Execution end for instance method
$time_end_instance = microtime(true);

// Total time is end-start time
$time_instance = $time_end_instance - $time_start_instance;

// Result is printed
echo "\nTotal execution time for instance method is: '$time_instance'";
?>