4. Understanding PHP Syntax and Tags

While PHP is embedded within HTML, it has strict rules regarding its own syntax.

Case Sensitivity

In PHP, variable names are case-sensitive, but built-in functions, keywords (if, echo, while), and class names are case-insensitive.

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Using caps for echo."; eChO "
Using mixed case for echo."; ?>

Every individual statement in PHP must be terminated with a semicolon (;). Forgetting the semicolon is one of the most common beginner errors.

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Note: Semicolons are not required after the closing PHP tag (?>) or after the closing brace of a block (}).

Comments are non-executable parts of the code used for documentation.