3) PHP Syntax


Basic PHP syntax:

The default extension for file is .php

Use .php extension for all php files even if it contains HTML code.

PHP Tags

Using PHP

For your PHP script to run you need to store your files inside server root folder in many cases it is htdocs or www or public_html

Viewing PHP files locally

Make sure local web server is running and then run the file using the URL like http://localhost/config.php

Check PHP configuration

Before starting you must check your PHP server is up and running and check how PHP is configured.

Create a blank file config.php

Load the file in the browser

If you have saved the file in www directory you can load the file with localhost/config.php

Before going further make sure you have your PHP file running to make sure everything is working correctly. Please make a note of main configuration file that is php.ini you may need to edit this file.

Comments and Whitespace

Comments in PHP are the lines of that are not read/executed. Comments make the code easier to read. Another reason to use comments is to disable part of code temporarily.

Difference Between single and double Quotes

In PHP we use single or double quotes for a string. You can use any of these, but there is an important difference in how they work.


If you run these code you will get an error. The problem here is that quotes must be in matching pairs.

How we can remove the error?

  1. Inserting a black slash in front of the apostrophe.

The syntax error has been corrected. This is known as an escape sequence.

Problem: The main problem with escape string is that it looks ugly when there are lots of single codes inside a string.

2) Using  double quotes:
Example 1:

Another difference between single and double quotes:

Example 1: When using single quotes to echo something

An output of this: This is

Example 1: When using double quotes to echo something

An output of this: