在PHP中使用strlen进行表单验证

Question

I have the following validation:

    if (empty($errors) === true) { 
        if (strlen($_POST['Description']) > 250) { //strlen counts the number of bytes
            $errors[] = 'Your description must be less than 250 characters long';
        }
    }

But if a user puts in a description more than 30 characters long this error will always be displayed. I have read that strlen returns the number of bytes rather than the number of characters in a string. I have tried mb_strlen to get character length but this doesn't work either. I feel like i am doing something obviously stupid, please help if you can.

Answer 1

Honestly i do not know of any encoding using 8 bytes for a character.

I think you "$_POST['Description']" may not contain only the data you want.

Do a

 var_dump($_POST['Description'])

And see what it shows.

on a sidenote:

if (strlen(trim($_POST['Description'])) > 250)

prevents whitespace to cause validation to fail.

Also note that you will have to specify the encoding to mb_strlen as the encoding of characters sent might not be the same as internal encoding.