What are the best practices for handling PHP version upgrades to avoid compatibility issues and errors in existing codebases?

When upgrading PHP versions, it is essential to review the deprecated features and changes in the new version to ensure compatibility with existing codebases. It is recommended to test the codebase thoroughly in a development environment before deploying the update to production. Additionally, using tools like PHP_CodeSniffer or PHP Compatibility Checker can help identify potential issues before they cause errors.

// Example of using PHP_CodeSniffer to check for compatibility issues
// Install PHP_CodeSniffer using Composer: composer require squizlabs/php_codesniffer
// Run the following command in the terminal: vendor/bin/phpcs --standard=PHPCompatibility --runtime-set testVersion 7.4 /path/to/your/codebase