regex101 quiz

If you find better and short solution pls let me know.

My Solution

1. Task 1 Check if a string contains the word word in it (case insensitive). If you have no idea, I guess you could try /word/.

   Regular Expression

   /\bword\b/i

2. Task 2 Use substitution to replace every occurrence of the word i with the word I (uppercase, I as in me). E.g.: i'm replacing it. am i not? -> I'm replacing it. am I not?. A regex match is replaced with the text in the Substitution field when using substitution.

   Regular Expression

/\bi\b/g

​ Substitution

I

3. Task 3 With regex you can count the number of matches. Can you make it return the number of uppercase consonants (B,C,D,F,..,X,Y,Z) in a given string? E.g.: it should return 3 with the text ABcDeFO!. Note: Only ASCII. We consider Y to be a consonant! Example: the regex /./g will return 3 when run against the string abc.

   Regular Expression

   /[B-DF-HJ-NP-TV-Z]/g

4. Task 4 Count the number of integers in a given string. Integers are, for example: 1, 2, 65, 2579, etc.

   Regular Expression

   /\d+/g

5. Task 5 Find all occurrences of 4 or more whitespace characters in a row throughout the string. Regular Expression

   /\s{4,}/g

6. Task 6 Oh no! It seems my friends spilled beer all over my keyboard last night and my keys are super sticky now. Some of the time whennn I press a key, I get two duplicates. Can you ppplease help me fix thhhis?

   Regular Expression

   /(.)\1{2}/g

   Substitution

   $1

7. Task 7 Validate an IPv4 address. The addresses are four numbered separated by three dots, and can only have a maximum value of 255 in either octet. Start by trying to validate 172.16.254.1.

   Regular Expression

   /^(?:(?:25[0-5]|2[0-4]\d|1\d{2}|[1-9]\d|\d)(?:.(?=\d)|$)){4}$/

8. Task 8 Strip all HTML tags from a string. HTML tags are enclosed in < and >. The regex will be applied on a line-by-line basis, meaning partial tags will need to be handled by the regex. Don't worry about opening or closing tags; we just want to get rid of them all. Note: This task is meant to be a learning exercise, and not necessarily the best way to parse HTML.

   Regular Expression

   ]*>|<[^<>]*>?

   Substitution

9. Task 9

   Verify that a given e-mail address is valid.

   We all know how complex emails are, but despite this, let's give it a try and see what we can come up with.

   You could start by trying to match contact@regex101.com (denoted as <local-part>@<domain>.<top-level-domain>).

   Regex

   ^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+.[A-Za-z]{2,}$

   error: Test 17/56: .example.co is not a valid domain.

10. Task 10