Variables in Hooks

[LMimo]

I have a variable problem in a hook. Can anyone help with why case 2 or case 3 do not work? Thanks in advance for any replies.

Case 1 (Works fine)

$test1 = "333";

build_something($test1, 0, 0)

Case 2 (Does not work)

$another1 is 333 when displayed in a template

$test1 = $another1;

build_something($test1, 0, 0)

Case 3 (Does not work)

$another1 is 333 when displayed in a template

build_something($another1, 0, 0)