## RegExp for strings of one or many 11 or no 11

**RE = (11) * **

**Rule**

All strings having one or many 11 or no 11 must be accepted and all other strings must be rejected by our Regular Expression.

## DFA for R.E = **(11) ***

**Accepted Strings (part of the language)**

These strings are part of the given language and must be accepted by our Regular Expression.

- 3 strings of Length 1 = (€).
- 3 strings of Length 2 = (11).
- 3 strings of Length 3 = (no string exists).
- 3 strings of Length 4 = (1111, no more strings).
- 3 strings of Length 7 = (no string exists).
- 3 strings of Length 10 = (1111111111, no more strings).
- 3 strings of Length 15 = (no string exists).
- 3 strings of Length 20= (11111111111111111111, no more strings).
- 3 strings of Length 25 = (no string exists).
- Many More similar strings.

**Rejected Strings (not part of the language)**

These strings are not part of the given language and must be rejected by our Regular Expression.

- 3 strings of Length 1 = (1).
- 3 strings of Length 2 = (no string exist).
- 3 strings of Length 3 = (111, no more strings).
- 3 strings of Length 5 = (11111, no more strings).
- 3 strings of Length 7 = (1111111, no more strings).
- 3 strings of Length 9 = (111111111, no more strings).
- 3 strings of Length 15 = (111111111111111, no more strings).
- 3 strings of Length 20 = (no string exist).
- 3 strings of Length 25 = (1111111111111111111111111, no more strings).
- Many More similar strings.

## More Examples of Regular Expression

- Regular Expression for no 0 or many triples of 0’s and many 1 in the strings.
- RegExp for strings of one or many 11 or no 11.
- A regular expression for ending with abb
- A regular expression for all strings having 010 or 101.
- Regular expression for Even Length Strings defined over {a,b}
- Regular Expression for strings having at least one double 0 or double 1.
- Regular Expression of starting with 0 and having multiple even 1’s or no 1.
- Regular Expression for an odd number of 0’s or an odd number of 1’s in the strings.
- Regular Expression for having strings of multiple double 1’s or null.
- Regular Expression (RE) for starting with 0 and ending with 1.
- RE for ending with b and having zero or multiple sets of aa and bb.
- A regular expression of the second last symbol is 1.
- RE for starting with 1 having zero or multiple even 1’s.
- Regular Expression for multiple a’s and multiple b’s.
- RE for exactly single 1 many 0’s |exactly single a many b.
- A regular expression for strings starting with aa and ending with ba.
- A regular expression for the language of all consecutive even length a’s.
- A regular expression for the language of all odd-length strings
- A regular expression for the language of all even length strings but ends with aa.
- A regular expression for the language of an odd number of 1s.
- A regular expression for the language of even length strings starting with a and ending with b in theory of automata.
- A regular expression for the language of all even length strings but starts with a.
- A Regular Expression for the Language of all strings with an even number of 0’s or even number of 1’s.
- A regular expression for the language of all those strings end with abb.
- A regular expression for string having must 010 or 101.
- 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. - A Regular Expression of all strings divisible by 4.
- A Regular Expression Strings that does not contain substring 110.

## 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.

**Tutorial covering the topics**

- Give a regular expression.
- Describe the strings of the regular expression.
- write a regular expression.
- create all strings from regular expression.
- Generate all strings from regular expression.
- Extract all strings from regular expression.
- Find all strings from regular expression.
- Examples of regular expression.

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