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The ClassLoader component provides tools to autoload your classes and cache their locations for performance.
Whenever you reference a class that has not been required or included yet, PHP uses the autoloading mechanism to delegate the loading of a file defining the class. Symfony provides three autoloaders, which are able to load your classes:
- The PSR-0 Class Loader: loads classes that follow the `PSR-0` class naming standard;
- The PSR-4 Class Loader: loads classes that follow the `PSR-4` class naming standard;
- MapClassLoader: loads classes using a static map from class name to file path.
Additionally, the Symfony ClassLoader component ships with a set of wrapper classes which can be used to add additional functionality on top of existing autoloaders: