@franciscaires, using a bang with 1 equal sign like so: if ($note['user_id'] != 1) would still work. Let me explain the difference for you.

A bang followed by a single equal sign checks if the $note['user_id'] is not equal to and allows any type whether it be a string or an integer. these will both produce the same result.

// Integer
if ($note['user_id'] != 1)

// String (notice the double quotes)
if ($note['user_id'] != "1")

A bang followed by double equal sign checks if the $note['user_id'] is equal to and checks for the same type either a string or an integer and will produce different results. so if $note['user_id'] was equal to 2 and was also an integer, then below would return true, as 2 does not equal 1 and is also an integer.

// Integer
if ($note['user_id'] !== 1)

But this example below would return false, even though 2 does not equal 1, it is a different type as the "1" is actually a string.

// String (notice the double quotes)
if ($note['user_id'] !== "1")

So != does not check for type where as !== is more strict and checks for type. This is the same for == and ===.

I hope that helps.

Introduction to Authorization