Checking if a file exists is a common task in PHP programming, and there are several different ways to do it. The most basic way is to use the file_exists() function, which takes a filename as an argument and returns true if the file exists and false if it does not.
There are a few other functions that can be used to check if a file exists, including is_file() and clearstatcache(). However, file_exists() is the most commonly used and is generally the most efficient.