PHP Introduction · Lesson 7 of 7

PHP Comments

Add useful single-line and block comments.

Lesson

Comments explain intent, constraints, or context that code alone does not make obvious. PHP supports // and # for single-line comments, and /* ... */ for block comments. Prefer clear names and simple code over comments that repeat each line. Update or remove a comment when the behavior changes; a stale comment is more confusing than no comment. Documentation comments beginning with /** can describe functions and types for editors and static analysis tools. Further guidance For every setup lesson, verify which PHP version and extensions are active in the same environment that runs the project. Keep a small reproducible script, use the command-line version output to diagnose configuration problems, and distinguish local development tools from production services. Practice task: Create a fresh example for PHP Comments. Predict the result before running it, then change one input and explain why the result changes. Test a normal case and one boundary or invalid case where it applies. Compare your output with the example and note one rule you would use in a real project.

Code examples

Commenting code

PHP

// Explain why this limit exists.
$maxAttempts = 5;

/* Use a block comment
   for longer context. */

Expected output

Comments are ignored when the PHP program runs.

Key points

Add useful single-line and block comments.
PHP must be processed by a PHP runtime before the browser receives its response.
Use the CLI to verify the runtime and run small scripts.

Your learning progress

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Optional practice

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