15000000-9

15.000.000-9

ABC123DEF12A

912345678 ó +56912345678 ó 56912345678

test@g.cn

1900 2024

ABCD12 o AB1234

Validación de fecha de formato europeo 13/12/2024

Validación para fechas en formato ISO 8601 como 2024-12-13

...

Purpose: This is supposed to be a learning process. The first 1-9 tasks are supposed to be done with using "standard" regex, ie, teach the user to use \s, \w, \d, aswell as backrefs and similar basic things. Later down the road, at task 10-13 we start introducing them to lookarounds. These are fairl...

In an HTML page, replace the text micro with µ. Oh, and don't screw up the code: don't replace inside or &entities;

Validate a line in quotes. Return one (and only one) backreference with the text. ie: quoted text from "quoted text". Note: a \ escapes any char, so \" is a valid escape.

Use substitution to put commas in all numbers to separate the thousands. ie: 12345678 → 12,345,678. The number could be in a sentence, and there may be more than one number in the sentence.

Replace every other character if it's a \d with * (only those in even positions: 2, 4, 6, etc). Example: a1b2cde3g45hi6 should become abcdeg4hi6

VALIDATING IP V4 1.1.1.1 2.2.2.2 3.3.3.3 4.4.4.4 5.5.5.5...

This is a test

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 @.).

For every occurrence of the char #, match the previous character and save it in a group (backreference). Example: for the text "a#bc# -#", set backreferences with a, c and -. You are not allowed to consume the hash character.

Check if a floating point number (e.g. 3.14159) is in a valid format.