Credit Card Carrier Prediction This regex is specifically designed to predict from the first few characters which carrier type the credit card number is.

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...

for finding and extracting numbers from the viewbox attribute. see also my generalized SVG number regex.

for correctly parsing numbers in SVG attributes like path d or viewBox with regex

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

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

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...

Antonio-Marcos O'Higgins González

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;