Answer 1

^ and $ are anchors, which indicates the start and end of a string. All regex patterns should use both.

$ indicates the end of a regex pattern, and anything that goes past it will not match. Here's an example, for the pattern "^g+quot;:
"ggggg" will match
"ggggx" will *not* match (because the g+ is the last item the regex searches for, and the additional x goes past the end)
"xgggg" will *not* match (because the x is before the pattern starts)