List of important Regular Expression
Here we have a list of important regular expressions used in the theory of automata and theory of computation. Hopefully, it will help in your semester examination.
 Regular Expression for no 0 or many triples of 0’s and many 1 in the strings – Click Here
 RegExp for strings of one or many 11 or no 11 – Click Here
 A regular expression for ending with abb – Click Here
 A regular expression for all strings having 010 or 101 – Click Here
 Regular expression for Even Length Strings defined over {a,b} – Click Here
 Regular Expression for strings having at least one double 0 or double 1 – Click Here
 Regular Expression of starting with 0 and having multiple even 1’s or no 1 – Click Here
 Regular Expression for an odd number of 0’s or an odd number of 1’s in the strings – Click Here
 Regular Expression for having strings of multiple double 1’s or null – Click Here
 Regular Expression (RE) for starting with 0 and ending with 1 – Click Here
 RE for ending with b and having zero or multiple sets of aa and bb – Click Here

A regular expression of the second last symbol is 1 – Click Here
 RE for starting with 1 having zero or multiple even 1’s – Click Here
 Regular Expression for multiple a’s and multiple b’s – Click Here
 RE for exactly single 1 many 0’s exactly single a many b – Click Here
 A regular expression for strings starting with aa and ending with ba – Click Here
 A regular expression for the language of all consecutive even length a’s – Click Here
 A regular expression for the language of all oddlength strings – Click Here
 A regular expression for the language of all even length strings but ends with aa. Click Here
 A regular expression for the language of an odd number of 1s – Click Here
 A regular expression for the language of even length strings starting with a and ending with b in theory of automata – Click Here
 A regular expression for the language of all even length strings but starts with a. Click Here
 A Regular Expression for the Language of all strings with an even number of 0’s or even number of 1’s. Click Here
 A regular expression for the language of all those strings end with abb. Click Here
 A regular expression for string having must 010 or 101. Click Here
 Regular expression of strings begin with 110
Regular expression of strings begin and end with 110
Regular expression of strings containing exactly three consecutive 1’s. Click Here  A Regular Expression of all strings divisible by 4. Click Here
 A Regular Expression Strings that does not contain substring 110. Click Here
Tutorial: Regular Expression
A detailed tutorial of the regular expression is here in the link of regular expression tutorial. This page contains the practice questions of regular expressions with solutions.