What are the recommended PHP functions for handling file operations and data manipulation?

When working with file operations and data manipulation in PHP, it is recommended to use functions like fopen, fwrite, file_get_contents, file_put_contents, and fclose for handling file operations. For data manipulation, functions like json_encode, json_decode, serialize, and unserialize can be used to convert data to and from different formats.

// Example of using fopen and fwrite to write data to a file
$file = fopen("example.txt", "w");
fwrite($file, "Hello, World!");
fclose($file);