When we want to match numbers or alphabets,
we use \w.
It can identify uppercase
and
lowercase characters.
It also matches underscores.
In the above example, we use \w
to match the character "R" and
the digit 0.
In the above example, \w matches
a single alphabet or number from the
different values. For example, it
checks the first character in "hello".
The first character is "h" which is a
match. Similarly, it finds a match with the
first value in all other variables.