Undefined index HTTP_HOST even though it is checked

Question

Here\'s the code:

if (isset($_SERVER[\'HTTP_HOST\']) === TRUE) {
  $host = $_SERVER[\'HTTP_HOST\'];
}

How is it possible to get an \"Undefined

Answer 1

I would normally omit the === TRUE, as it's not needed here because isset() returns a boolean, but that shouldn't stop your code from working.

I would also set $host to a sensible default (depends on your application) before the if statement. I have a general rule to not introduce a new variable inside a conditional if it's going to be referred to later.

$host = FALSE;    // or $host = ''; etc. depending on how you'll use it later.
if (isset($_SERVER['HTTP_HOST'])) {
  $host = $_SERVER['HTTP_HOST'];
}