Question

$GetUid = $dbConnect->prepare("SELECT UID FROM users WHERE username = :username");
$GetUid->execute($RegisterData3);
$UserID = $GetUid->fetch();

why does it return array not a string ?

var_dump(‘$UserID’) says

array
  'UID' => string '45' (length=2)
  0 => string '45' (length=2)

it should be

array
  'UID' => string '45' (length=2)

update*
what about the 0 ? where does it came from ? thanks for the replies.

Answer 1

You didn’t specify a fetch_style parameter. It returns FETCH_BOTH by default, which is an array. Here are the options and how to specify it:
http://php.net/manual/en/pdostatement.fetch.php

EDIT: Also, it will always return an array, even if there’s only one column, because a row can contain multiple attributes. You can use FETCH_ASSOC and then specify your column name to get the data, or, if you just use fetch() like you did, the array is indexed by both the column name and the 0-indexed column number.