Basic PHP Syntax

Understanding the basic syntax of PHP is essential for anyone beginning their journey in server-side scripting. PHP’s flexibility and popularity stem from its ease of use and simple, readable code structure. In this article, we’ll explore the core components of PHP syntax, from script structure and tags to comments and basic statements. By the end, you will be able to confidently interpret and write entry-level PHP scripts.

PHP Script Structure and Tags

PHP scripts are embedded within HTML or written in standalone files. To define PHP code in a file, special tags are required to indicate where the PHP script starts and ends. The most common opening and closing tags are:

<?php
    // PHP code goes here
?>

All PHP code must be included inside <?php and ?> tags. This markup signals the server to process the enclosed code as PHP.

Case Sensitivity in PHP

PHP is a case-sensitive language in certain aspects. This means that variable names are case-sensitive, while function names and keywords are not. For example, the following variables are distinct from each other:

$message = "Hello";
$Message = "World";

However, both echo and ECHO would work identically when outputting values.

Statements and Semicolons

Each instruction or statement in PHP must end with a semicolon ;. This is crucial, as omitting the semicolon can result in syntax errors. Here is an example of a valid PHP statement:

echo "Welcome to PHP!";

Semicolons help the PHP interpreter distinguish where one command ends and another begins.

Adding Comments in PHP

Comments are notes you add to your code that are ignored when the script is executed. They are useful for documentation and making the code easier to understand. PHP supports three ways to write comments:

• Single-line with double slashes //
• Single-line with hash #
• Multi-line with /* ... */

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

Echo and Print Statements

Outputting text and variable values is fundamental in PHP scripts. The echo and print statements are commonly used for this purpose. They both display information on the web page, but echo is slightly faster and can take multiple parameters.

echo "Hello, World!";
print "Hello, PHP!";

Both functions can output variables, HTML, or static text to the browser.

Whitespace and Readability

PHP largely ignores whitespace (spaces, tabs, and newlines) between statements and expressions. Developers use whitespace and indentation to make code more readable. Proper formatting is considered best practice:

<?php
    echo "Clean code is easier to maintain.";
?>

Basic Rules of PHP Syntax

• All PHP code must be inside <?php ... ?> tags.
• Statements end with a semicolon (;).
• Variable names start with a dollar sign ($) and are case-sensitive.
• Function and keyword names are not case-sensitive.
• Use comments for documentation or to temporarily deactivate code segments.
• Whitespace is ignored, but good formatting aids readability.

Example: Your First PHP Script

To consolidate what you’ve learned, here’s a simple PHP script that prints a message on your screen:

<?php
// Display a welcome message
echo "Welcome to the world of PHP!";
?>

Try saving the code above in a file named hello.php and open it with your web server. You should see the welcome message displayed in your browser.

Common Syntax Errors to Avoid

Syntactical mistakes are common for beginners. Here are some issues to watch out for:

• Forgetting the semicolon at the end of a statement.
• Not enclosing PHP code within the proper opening and closing tags.
• Mismatched or missing quotes and parentheses.
• Incorrect variable naming or case usage.

Conclusion

Mastering basic PHP syntax is a crucial step before working with more complex logic, functions, or database connections. By understanding how scripts are structured, how statements end, and how to document your code with comments, you build a strong foundation for all future PHP development. Reference these principles frequently as you continue exploring PHP and developing dynamic, server-powered applications.