Table of Contents
- 1 What is regular expression corresponding to the language of strings of even lengths over the alphabet of a B )?
- 2 Which of the following is a regular expression for the set of all strings over the alphabet A that has an even number of A’s?
- 3 What is the regular expression symbol matching zero or more specific characters?
- 4 What does [^]* mean in regex?
- 5 Is it possible to match the whole line of a string?
What is regular expression corresponding to the language of strings of even lengths over the alphabet of a B )?
Solution: Since any string of even length can be expressed as the concatenation of strings of length 2 and since the strings of length 2 are aa, ab, ba, bb, a regular expression corresponding to the language is ( aa + ab + ba + bb )*. Note that 0 is an even number.
What is the regular expression for the strings that have even length and start with 0 ‘?
Write the regular expression for the language over ∑ = {0} having even length of the string. Solution: The regular expression has to be built for the language: L = {ε, 00, 0000, 000000….}
Which of the following is a regular expression for the set of all strings over the alphabet A that has an even number of A’s?
Even number of a’s : The regular expression for even number of a’s is (b|ab*ab*)*.
What is a regular expression for a set of strings of 0s and 1s with even number of 0s?
All strings containing an even number of 0’s: 1*+ (1*01*0)*1*. The first expression 1* describes the strings with no 0’s. The expression (1*01*0)*1* describes the strings with at least two 0’s.
What is the regular expression symbol matching zero or more specific characters?
3. What is the Regular Expression Matching Zero or More Specific Characters? Explanation: Zero or Specific Expression matching can be done only by a single character that is*. 4.
Can regex match words with a maximum length?
I would like to know the regex to match words such that the words have a maximum length. for eg, if a word is of maximum 10 characters in length, I would like the regex to match, but if the length exceeds 10, then the regex should not match. I tried
What does [^]* mean in regex?
This means “match any number of characters that are either whitespace or non-whitespace” – effectively “match any string”. Another option that only works for JavaScript (and is not recognized by any other regex flavor) is [^]* which also matches any string.
How do I match any number of characters in a string?
If you’re using JavaScript, which doesn’t have a “dotall” option, try [\\s\\S]*. This means “match any number of characters that are either whitespace or non-whitespace” – effectively “match any string”. Another option that only works for JavaScript (and is not recognized by any other regex flavor) is [^]*which also matches any string.
Is it possible to match the whole line of a string?
Yes. This string is part of a bigger string that contains words of several formats – dates, emails, urls etc all in a tab delimited format. I am thinking to write a composite regex to match the whole line.