# A Regular Expression of all strings divisible by 4

A Regular Expression of all strings divisible by 4 defined over {a,b}.

## Regular Expression: {(1+0) (1+0) (1+0) (1+0)}*

Accepted Strings (part of the language)

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

• The strings  of length 01 = {no string exist}
• The strings  of length 02 = {no string exist}
• The strings  of length 03 = {no string exist}
• The strings  of length 04= {1111, 1010, 1001,…. and many more similar strings.}
• The strings  of length 07 = {no string exist}
• The strings  of length 08 = {10101010, 11001100, 11000011,…. and many more similar strings.}
• The strings  of length 10 = {no string exist}
• The strings  of length 12 = {111111000000, 111000111000, 101010101010,…. and many more similar strings.}
• The strings  of length 20 = {11111000001111100000, 10101010101010101010, 11100011100101001101,…. and many more similar strings.}
• The strings  of length 25 = {no string exist}
• And 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.

• The strings  of length 01 = {0, 1,…. and many more similar strings.}
• The strings  of length 02 = {11, 10, 00,…. and many more similar strings.}
• The strings  of length 03 = {111, 101, 000,…. and many more similar strings.}
• The strings  of length 04 = {no string exist}
• The strings  of length 07 = {1100110, 1111111, 0000111,…. and many more similar strings.}
• The strings  of length 10 = {1100110011, 1111100000, 1010101010,…. and many more similar strings.}
• The strings  of length 15 = {101010101010101, 111110001111000, 111111100000000,…. and many more similar strings.}
• The strings  of length 20 = {no string exist}
• The strings  of length 25 = {no string exist}
• And many more similar strings.

Regular Expression of set of all strings divisible by 4

Regular Expression: {(b+a) (b+a) (b+a) (b+a)}*

Accepted Strings (part of the language)

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

• The strings  of length 1 = {no string exist}
• The strings  of length 2 = {no string exist}
• The strings  of length 3 = {no string exist}
• The strings  of length 4= {bbbb, baba, baab,…. and many more similar strings.}
• The strings  of length 7 = {no string exist}
• The strings  of length 8 = {babababa, bbaabbaa, bbaaaabb,…. and many more similar strings.}
• The strings  of length 10 = {no string exist}
• The strings  of length 12 = {bbbbbbaaaaaa, bbbaaabbbaaa, babababababa,…. and many more similar strings.}
• The strings  of length 20 = {bbbbbaaaaabbbbbaaaaa, babababababababababa, bbbaaabbbaababaabbab,…. and many more similar strings.}
• The strings  of length 25 = {no string exist}
• and 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.

• The strings  of length 1 = {a, b,…. and many more similar strings.}
• The strings  of length 2 = {bb, ba, aa, ab}
• The strings  of length 3 = {bbb, bab, aaa,…. and many more similar strings.}
• The strings  of length 4 = {no string exist}
• The strings  of length  7 = {bbaabba, bbbbbbb, aaaabbb,…. and many more similar strings.}
• The strings  of length 10 = {bbaabbaabb, bbbbbaaaaa, bababababa,…. and many more similar strings.}
• The strings  of length 15 = {bababababababab, bbbbbaaabbbbaaa, bbbbbbbaaaaaaaa,…. and many more similar strings.}
• The strings  of length 20 = {no string exist}
• The strings  of length 25 = {no string exist}

## 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.