Regular Expression
tip
Source of truth by testing.
Word Boundary Marker
\b
is used to mark the boundary of a word. But when put besides a non-word, it matches if it's at boundary with a word. It's definition is given as
(^\w|\w$|\W\w|\w\W)
So for example, "a#\b"
matches "a#a"
but not "a# "
.
And \w
is [a-zA-Z0-9_]
.