PHP Syntax

PHP (Hypertext Preprocessor) code starts with <?php and ends with ?>. Every PHP statement ends with a semicolon ;.

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

Comments in PHP

Comments are used to explain code and are ignored by the PHP engine. You can use:

• // for single-line comments
• /* ... */ for multi-line comments

<?php
  // This is a single-line comment
  /*
    This is a
    multi-line comment
  */
  echo "Welcome to PHP!";
?>

Case Sensitivity

Function names are not case-sensitive, but variables are:

<?php
  ECHO "Hello";
  echo "World";
  $msg = "Test";
  echo $Msg; // Error: undefined variable
?>