PHP Professional Standards & Competencies 4

Question 1

Which Composer command should you run before deploying a PHP application to production?

Accepted Answer

composer install --no-dev --optimize-autoloader

Answer

`composer install --no-dev --optimize-autoloader` installs only production dependencies and generates an optimized classmap for faster autoloading.

Question 2

What is the purpose of the `composer.lock` file in a professional PHP project?

Accepted Answer

Pin the exact resolved versions of all dependencies so every install is reproducible

Answer

The lockfile records exact package versions and hashes, ensuring every developer and deployment environment uses the identical dependency tree.

Question 3

In PHP, what is the professional use of interfaces over concrete class type hints in method signatures?

Accepted Answer

Programming to interfaces decouples code from specific implementations, making it easier to swap or mock dependencies

Answer

Type-hinting against an interface rather than a concrete class follows the Dependency Inversion Principle and enables substituting alternative implementations without changing the consuming code.

Question 4

Which of the following best describes the 'Boy Scout Rule' applied to PHP development?

Accepted Answer

Leave the code cleaner than you found it — fix small issues whenever you touch a file

Answer

The Boy Scout Rule encourages incremental improvement: rename a confusing variable, remove dead code, or add a missing type hint each time you edit a file.

Question 5

What is a 'feature flag' and why might a professional PHP team use one?

Accepted Answer

A runtime switch that enables or disables a feature without deploying new code, allowing safe gradual rollout

Answer

Feature flags let teams deploy code to production while keeping features hidden, enabling A/B testing, canary releases, and instant rollback without redeployment.

PHP - PHP Programming Language Practice Test

PHP - PHP Programming Language Practice Test

PHP Professional Standards & Competencies 4