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.

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

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...

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

Validación de fecha de formato europeo 13/12/2024

ABCD12 o AB1234

1900 2024

test@g.cn

912345678 ó +56912345678 ó 56912345678

ABC123DEF12A

15.000.000-9

15000000-9

Antonio-Marcos O'Higgins González

This is made to validate an ISO 8601 input in a Terraform variable validation block: validation { condition = can(regex("^P(\\d+Y)?(\\d+M)?(\\d+D)?(T(\\d+H)?(\\d+M)?(\\d+S)?)?$", var.value)) error_message = "The value must be a valid ISO 8601 duration string representing time. (e.g. PT...

Tested in 2024 with various share/embed methods on YouTube video page

Allowing all firsnames written with Latin text like Björn or D'Mariüsz

for correctly parsing numbers in SVG attributes like path d or viewBox with regex v2: added support for scientific notation

for finding and extracting numbers from the viewbox attribute. see also my generalized SVG number regex. v2: added support for scientific notation

Matches some number of a's followed by the same number of b's, usually written as a^nb^n for all natural numbers n. For regular expressions as formally defined in formal language theory, this is impossible, but modern day regex engines can do far more than match just regular languages. Note that eve...