How a PHP request starts and ends

Introduction

PHP runs code when a web page is requested and stops when the page is done. This helps create dynamic websites.

When a user visits a webpage that uses PHP to show content.

When a form is submitted and PHP processes the data.

When a server needs to run PHP code to get information from a database.

When you want to create a page that changes based on user input.

When you want to send an email or save data after a user action.

Syntax

PHP

<?php
// PHP code here
?>

PHP code starts with <?php and ends with ?>.

The server runs the PHP code between these tags when the page is requested.

Examples

This example shows a simple PHP script that prints text to the page.

PHP

<?php
echo "Hello, world!";
?>

This example shows PHP code running when the page loads and then stopping after finishing.

PHP

<?php
// Start of PHP request
$name = "Alice";
echo "Welcome, $name!";
// End of PHP request
?>

Sample Program

This program shows how PHP code runs from start to end during a page request. It prints a message and then stops.

PHP

<?php
// This simulates a PHP request

// Start: PHP code runs when page is requested
$message = "Hello from PHP!";
echo $message;

// End: PHP stops after sending output
?>

Important Notes

PHP runs only when a page is requested and stops after sending the response.

Each request is separate; PHP does not keep running after the page loads.

Use PHP tags to tell the server where your PHP code starts and ends.

Summary

PHP code runs between <?php and ?> tags.

A PHP request starts when a page is requested and ends after the server sends the response.

Each request is independent and runs the PHP code fresh every time.