Warning: session_start(): Setting option 'session.hash_function' failed in on line

When I tried to add options parameters to session_start() php function, I got this warning

"Warning: session_start(): Setting option 'session.hash_function' failed in  on line "

I was using the full name of the parameter like this

session_hash_function

 

But the session_start function requires these parameters without the prefix "session", So the new parameter will be "hash_function"

session_start(["hash_function" =>  5 ]);

Notice: in PHP7.1: Session IDs will no longer be hashed upon generation. With this change brings about the removal of the following four ini settings:

    session.entropy_file
    session.entropy_length
    session.hash_function
    session.hash_bits_per_character