Composer for PHP

Question 1

Q: What is Composer in PHP?

Answer 1

A: A dependency manager for PHP projects.

Question 2

Q: How do you install Composer globally?

Answer 2

php -r “copy(‘https://getcomposer.org/installer’, ‘composer-setup.php’);”
php composer-setup.php
mv composer.phar /usr/local/bin/composer

Question 3

Q: How do you verify Composer is installed?

Answer 3

A: Run composer –version.

Question 4

Q: What is the default file used by Composer to manage dependencies?

Answer 4

A: composer.json.

Question 5

Q: What command creates a new composer.json file?

Answer 5

A: composer init.

Question 6

Q: How do you install a package with Composer?

Answer 6

A: composer require vendor/package-name.

Question 7

Q: What command installs all dependencies listed in composer.json?

Answer 7

A: composer install.

Question 8

Q: How do you update all dependencies to their latest versions?

Answer 8

A: composer update.

Question 9

Q: How do you install a specific version of a package?

Answer 9

A: composer require vendor/package-name:^1.2.

Question 10

Q: How do you install dependencies without autoloading?

Answer 10

A: composer install –no-autoloader.

Question 11

Q: What is the purpose of the require section in composer.json?

Answer 11

A: Specifies the project’s dependencies.

Question 12

Q: What is the require-dev section used for?

Answer 12

A: Lists dependencies needed only for development.

Question 13

Q: How do you specify a PHP version requirement in composer.json?

Answer 13

“require”: {
“php”: “>=7.4”
}

Question 14

Q: What is the autoload section in composer.json for?

Answer 14

A: Defines how classes and files are loaded automatically.

Question 15

Q: What is the scripts section in composer.json?

Answer 15

A: Defines custom scripts that can be executed with Composer commands.

Question 16

Q: What is Composer’s autoloader file?

Answer 16

A: vendor/autoload.php.

Question 17

Q: How do you include Composer’s autoloader in your project?

Answer 17

A: require ‘vendor/autoload.php’;.

Question 18

Q: What is PSR-4 autoloading in Composer?

Answer 18

A: A standard for autoloading classes using namespaces and directory structure.

Question 19

Q: How do you define PSR-4 autoloading in composer.json?

Answer 19

“autoload”: {
“psr-4”: {
“Namespace\”: “src/”
}
}

Question 20

Q: How do you regenerate the autoloader?

Answer 20

A: composer dump-autoload.

Question 21

Q: How do you show installed packages?

Answer 21

A: composer show.

Question 22

Q: How do you show details about a specific package?

Answer 22

A: composer show vendor/package-name.

Question 23

Q: How do you remove a package?

Answer 23

A: composer remove vendor/package-name.

Question 24

Q: How do you check for outdated dependencies?

Answer 24

A: composer outdated.

Question 25

Q: How do you list globally installed Composer packages?

Answer 25

A: composer global show.

Question 26

Q: What is the purpose of composer.lock?

Answer 26

A: Locks dependency versions to ensure consistency across environments.

Question 27

Q: Should you commit composer.lock to version control?

Answer 27

A: Yes, to ensure consistent dependency versions for all developers.

Question 28

Q: How do you install dependencies exactly as listed in composer.lock?

Answer 28

A: composer install.

Question 29

Q: What command updates the composer.lock file?

Answer 29

A: composer update.

Question 30

Q: How do you check for changes in composer.lock?

Answer 30

A: Use version control tools like git diff.

Question 31

Q: How do you install only production dependencies?

Answer 31

A: composer install –no-dev.

Question 32

Q: How do you install only development dependencies?

Answer 32

A: Use composer require –dev.

Question 33

Q: How do you run a custom script defined in composer.json?

Answer 33

A: composer run-script script-name.

Question 34

Q: How do you check the current environment in Composer?

Answer 34

A: Use the COMPOSER_DEV_MODE environment variable.

Question 35

Q: How do you validate the syntax of composer.json?

Answer 35

A: composer validate.

Question 36

Q: What is the config command used for in Composer?

Answer 36

A: To set or get configuration options, e.g., composer config.

Question 37

Q: How do you create a global Composer package?

Answer 37

A: Install it globally with composer global require vendor/package-name.

Question 38

Q: What does the prefer-dist flag do during installation?

Answer 38

A: Downloads pre-built distribution archives instead of cloning repositories.

Question 39

Q: How do you create a Composer package?

Answer 39

A: Add a composer.json file to the project and publish it to Packagist.

Question 40

Q: How do you specify a package repository other than Packagist?

Answer 40

A: Add a repositories section in composer.json.