Default Syntax of PHP

PHP code is written inside PHP tags and executed on the server.

Basic PHP Syntax

<?php
   // PHP code goes here
?>

Important Rules

• PHP statements end with a semicolon (;)
• PHP is case-sensitive for variables
• Keywords like echo, if, while are not case-sensitive

Example

<?php
echo "Welcome to PHP";
?>

Exam Point: PHP code must be written inside <?php ?> tags.

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Styles of PHP Tags

PHP supports different tag styles to write PHP code.

1. Standard PHP Tags (Recommended)

<?php
echo "Hello PHP";
?>

• Verified: Most commonly used
• Verified: Supported on all servers

2. Short Open Tags

<?
echo "Hello PHP";
?>

• Warning: Not recommended
• Warning: May be disabled on some servers

3. Short Echo Tags

<?= "Hello PHP"; ?>

• Use: Used for quick output
• Support: Mostly supported in modern PHP versions

4. ASP Style Tags

<%
echo "Hello PHP";
%>

• Status: Deprecated
• Status: Not used in modern PHP

Comparison Table

Exam Tip: Standard PHP tags are the safest and most recommended.

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Comments in PHP

Comments are used to explain code and are ignored by the PHP interpreter.

1. Single-Line Comment

// This is a single-line comment
# This is also a single-line comment

2. Multi-Line Comment

/*
This is a
multi-line comment
*/

Why Use Comments?

• Improves code readability
• Helps in debugging
• Useful for documentation

Exam Line: Comments are non-executable lines used to explain PHP code.