$filename1 = "myfile.txt"; if(isFileName($filename1)){ echo "Valid filename"; } else { echo "Invalid filename"; }
$filename2 = "my:file.txt"; if(isFileName($filename2)){ echo "Valid filename"; } else { echo "Invalid filename"; }In the first example, the string "myfile.txt" is passed to the isFileName function, which returns true because it is a valid filename. In the second example, the string "my:file.txt" is passed to the function, which returns false because it contains an invalid character (the colon). It is not clear from the question which package library is being referred to. The isFileName function may either be a built-in function of PHP or part of a third-party library.