Composer require and dependency management in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the composer require command do?

It adds a new package to your project and updates the composer.json and composer.lock files automatically.

beginner

What is the purpose of the composer.lock file?

It locks the exact versions of all installed packages to ensure consistent installs across different environments.

intermediate

How does Composer handle version conflicts between packages?

Composer tries to find a set of package versions that satisfy all version constraints. If it can't, it shows an error and stops the installation.

beginner

What is the difference between require and require-dev in Composer?

require is for packages needed in production, while require-dev is for packages only needed during development, like testing tools.

beginner

Why should you commit composer.lock to version control?

Committing composer.lock ensures everyone uses the same package versions, avoiding unexpected bugs caused by different dependencies.

What happens when you run composer require monolog/monolog?

A Composer updates PHP version.

B Only <code>composer.json</code> is updated, no packages installed.

C Monolog package is added and <code>composer.json</code> and <code>composer.lock</code> are updated.

D Composer removes all existing packages.

The composer require command adds the package and updates both composer.json and composer.lock.

Which file ensures consistent package versions across different machines?

A <code>vendor/composer</code>

B <code>composer.json</code>

C <code>autoload.php</code>

D <code>composer.lock</code>

composer.lock locks the exact versions of installed packages.

If two packages require conflicting versions of the same dependency, what does Composer do?

A Shows an error and stops installation.

B Ignores the conflict and installs both versions.

C Automatically picks the newest version.

D Removes one of the conflicting packages.

Composer stops and shows an error if it cannot resolve version conflicts.

Which command installs packages listed in require-dev?

A <code>composer install --no-dev</code>

B <code>composer install</code>

C <code>composer update --no-dev</code>

D <code>composer dump-autoload</code>

Running composer install installs both require and require-dev packages by default.

Why is it important to commit composer.lock to your project repository?

A To ensure all developers use the same package versions.

B To speed up Composer commands.

C To avoid installing any packages.

D To update PHP automatically.

Committing composer.lock ensures consistent dependency versions for all developers.

Explain how composer require helps manage dependencies in a PHP project.

Think about what files change and what happens to the package.

Describe the role of composer.lock and why it is important to commit it to version control.

Consider what happens if different developers have different versions.