In the provided code snippet, what improvements or optimizations could be made to enhance the performance or readability of the script for processing file data in PHP?

One improvement that could enhance the performance and readability of the script is to use the file() function instead of fopen() and fgets() to read the file data into an array. This simplifies the code and makes it more concise. Additionally, using file_get_contents() can also be a more efficient way to read the entire file contents into a string.

// Read file data into an array using file()
$fileData = file('data.txt');

// Read file data into a string using file_get_contents()
$fileContents = file_get_contents('data.txt');