Basic Syntax Overview

Understanding the basic syntax of PHP is essential for anyone starting their journey in web development with this popular server-side scripting language. In this section, we will cover the fundamental structure and components of PHP code, including how to write, save, and execute simple scripts. Mastery of the syntax will provide a strong foundation for building dynamic websites and applications.

PHP Tag Syntax

PHP scripts are embedded within web pages using special tags. These tags tell the server where the PHP code begins and ends. Standard PHP code blocks are started and closed by:

<?php
// PHP code goes here
?>

Everything written between these tags is processed by the PHP engine. Content outside the tags will be treated as regular HTML.

Writing Your First PHP Statement

Like most programming languages, PHP scripts are made up of statements. The simplest way to output text is by using the echo statement, which prints data to the browser:

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

Each PHP statement should end with a semicolon (;). This marks the conclusion of a single instruction for the interpreter.

Comments in PHP

Comments are ignored by the PHP engine and serve to document or explain code. PHP supports both single-line and multi-line comments:

• Single-line comment using double slashes: //
• Single-line comment using hash: #
• Multi-line comment: /* ... */

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

Case Sensitivity in PHP

PHP is case-sensitive in certain aspects. Variable names are case-sensitive, so $Name and $name refer to different variables. However, PHP function names and keywords are case-insensitive. For example, echo and ECHO are equivalent.

Whitespace and Indentation

PHP ignores extra whitespace, such as spaces, tabs, and newlines, between statements. Proper indentation is encouraged to improve code readability and maintain best practices within your scripts.

<?php
   echo "This";
      echo "is";
  echo "valid PHP code!";
?>

PHP File Structure and Execution

PHP files have the extension .php. When these files are accessed through a server configured with PHP, the server processes the PHP code and sends the output (often HTML) to the browser. Any code outside the PHP tags is sent to the client as-is.

Outputting Data in PHP

Besides echo, PHP provides several methods to output data. Here are the most common:

• echo – Outputs one or more strings.
• print – Similar to echo, but behaves like a function and returns a value.
• print_r() – Outputs structured information, useful for arrays and objects.
• var_dump() – Displays detailed type and value information, useful for debugging.

<?php
echo "Hello";
print "World!";
print_r([1, 2, 3]);
var_dump(42);
?>

Summary: Key Takeaways on PHP Syntax

• PHP code is enclosed in <?php ... ?> tags.
• Statements end with a semicolon (;).
• Comments can use //, #, or /* ... */ notation.
• Variable names are case-sensitive, but keywords and function names are not.
• Whitespace is ignored; however, clear formatting is encouraged for readability.
• PHP files use the .php extension and are processed server-side.

With these basics in mind, you are ready to move forward and explore more complex aspects of PHP. Becoming comfortable with the fundamental syntax is crucial to writing effective and error-free PHP code as you progress through this tutorial series.