Matching text with Special meta-characters using Regular Expressions

Regex are more powerful and we want to do more than simply search for literal pieces of text. There are certain reserved meta-characters with Special uses and meaning. These "metacharacters" are: the square bracket [...], the backslash \, the caret ^, the dollar sign $, the period or dot ., the vertical bar or pipe symbol |, the question mark ?, the asterisk or star *, the plus sign +, the round bracket (…) and the Curly Brace {…}.

Below table well explain us with the usability of each metacharacter.

Table 1: Regular Expressions Metacharacters
meta-character	Definition ( or Use)
^	Start of a string.
$	End of a string.
.	. Any character (except \n newline)
\|	Alternation: state to another and back again.
{…}	Explicit quantifier notation.
{n}	Repeat n times.
{n,m}	Repeat at least n, but no more than m times.
{n,}	Repeat at least n times.
(…)	Explicit set of characters to match.
*	Repeat any number of times.
+	Repeat one or more times.
?	Repeat zero or one time
\	Preceding "\" makes all the metacharacter as a literal instead of a special character.