How to use PHP to check form field for specific value?

Question

The value '7' would need to be inserted or else the form field will be invalid; so invalid with all other numbers then 7.

if(empty($_POST['captcha']))
{
    $this->add_error("Did you solve the captcha?");
    $ret = false;
}

Works to check if any value -- but I need to specify, must be 7.

if(strlen($_POST['captcha']) =!7) // tried this but form completely died or disappeared
{
    $this->add_error("Did you solve the captcha?");
    $ret = false;
}

Hey @Jack this was the answer, man. If you wanted to post – Dr Upvote Sep 03 '14 at 00:12 — Dr Upvote, Sep 03 '14 at 00:12

score 2 · Accepted Answer · answered Sep 03 '14 at 00:15

There are two things to note here:

You shouldn't use empty() here, because "0" is considered empty as well and it seems like it could be the answer of an equation; use isset() instead to just check whether the value is part of the request.
You're trying to check the length of $_POST['captcha'] instead of comparing its value.

So:

if (!isset($_POST['captcha']) || $_POST['captcha'] != 7) {
    $this->add_error('Did you solve the captcha?');
    $ret = false;
}

score 1 · Answer 2 · edited May 23 '17 at 12:21

1

You have two problems:

=! should be !=. See comparison operators.

if(strlen($_POST['captcha']) != 7)

You also need to turn on error reporting.

edited May 23 '17 at 12:21

Community

1
1

answered Sep 02 '14 at 23:55

John Conde

217,595
99
455
496

How to use PHP to check form field for specific value?

2 Answers2