基本的php问题

Question

New to php. Can anyone tell me what this means?

if(!isset($_POST['submit']) || $Email!=$ConfirmEmail || !$info_str || !$valid_email)

Answer 1

It's a bunch of checks to see if certain variables/post fields aren't set, or if the Email and ConfirmEmail variables don't match.

Broken down into pieces:

if(                             < IF
    !isset($_POST['submit'])    < NOT (IS SET (POST FIELD 'submit'))
    ||                          < OR
    $Email!=$ConfirmEmail       < VARIABLE 'Email' IS NOT EQUAL TO VARIABLE 'ConfirmEmail'
    ||                          < OR
    !$info_str                  < NOT (VARIABLE 'info_str' IS A TRUE VALUE)
    ||                          < OR
    !$valid_email               < NOT (VARIABLE 'valid_email' IS A TRUE VALUE)
)

Note that due to the ! "nots", many of the conditions are actually the opposite of what they would otherwise be (i.e. positive test if $valid_email is actually a false value - such as being null).