CS 328 - Week 9 Lecture 2 - 2016-03-23

*   intro to PHP sessions, continued

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*   from course text: Section 14.3, p. 556:

    IF, for SOME reason, you want to get
    rid of the current session and immediately
    begin a new session, you have to REGENERATE
    a NEW session id and then restart:

    session_destroy();
    session_regenerate_id(TRUE);
    session_start();

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*   note: you can remove a key (and its value) 
    from an associative array using the unset function:

    unset($_SESSION['fave_sound']);

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*   we "talked through" an approach to a single PHP document
    using sessions to control a sequence of responses
    to a user at the end of class on Monday (Week 9 Lecture 1);

    we now DEMOED this in class developing 
    try-trio.php

    *   (and transformed complain_and_exit.php from a stub
        to operational after class -- check it out,
	and let me know if you have any questions about
	it)

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*   note: looked up after class:

    PHP has a function trim that expects a string, and
    returns that string with any leading or trailing
    white space removed;

    (this is now used in the
    posted version of try-trio.php to allow it to
    complain and exit if a silly person tries to
    enter a name, quest, or color consisting of,
    for example, just blanks... 8-) )