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

IF
There is no element named 'submit' in the _POST array
OR
if $Email is not equal to $ConfirmEmail
OR
$info_str is empty
OR
$valid_email is zero

then do something...mostly split an error to the user.

Effectively it does error checking, ensuring the request has come through a form submit, has a valid email that matches the confirm email and has a non empty $info_str variable value.

Answer 2

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 (ie positive test if $valid_email is actually a false value - such as being null ).

Answer 3

It is form validator. If form is submitted and email equal predefined email, and other variables are defined.

Answer 4

if (                          // if
    !isset($_POST['submit'])  // 'submit' element in $_POST array is not set
    ||                        // or
    $Email != $ConfirmEmail   // $Email does not equal $ConfirmEmail
    ||                        // or
    !$info_str                // $info_str is false
    ||                        // or
    !$valid_email             // $valid_email is false
)

! negates a value. 'foo' would usually be regarded as true , the negated !'foo' is false . '' (an empty string) is usually regarded as false , the negated !'' is true . See PHP type comparison tables and Logical Operators .

Answer 5

我只需要重新排列结构即可解决我的问题。