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]I am little confused on how to use regular expression to find a sub string in string .
I know how to remove unwanted characters using regular expression , but I do not get how "match" works

I found few "tutorials" and so far no luck.

Here is my next tutorial I will try - Regex Tutorial, Examples and Reference - Regexp Patterns[^]

I would appreciative if somebody recommends a source to answer my question.
Please no u-tube.

What I have tried:

Different tutorials and coding in C++
Updated 7-Jul-22 16:12pm
k5054 7-Jul-22 17:16pm     CRLF
Why no YouTube? Jason Turner's C++ weekly column did a short intro to C++ regex some time ago. Its only 8:30 minutes long, so a quick watch, and quite clear and understandable. It does assume that you know a little bit of regex's already, so if you're struggling with how to build a regex, it won't be too helpful. If you're just trying to figure out the match portion, this might be enough to get you going. If you're learning C++, some of his columns might help clear up some of the mysteries.
Dave Kreskowiak 7-Jul-22 18:52pm     CRLF
Because most YouTubers have no idea how to code let alone teach anything.

The tutorial page seems to fit.

std regex C++11 Standard Library Regular Expressions


std Regular expressions library (C++11)
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Just a few interesting links to help building and debugging RegEx.
Here is a link to RegEx documentation:
perlre -[^]
Here is links to tools to help build RegEx and debug them:
.NET Regex Tester - Regex Storm[^]
Expresso Regular Expression Tool[^]
RegExr: Learn, Build, & Test RegEx[^]
Online regex tester and debugger: PHP, PCRE, Python, Golang and JavaScript[^]
This one show you the RegEx as a nice graph which is really helpful to understand what is doing a RegEx: Debuggex: Online visual regex tester. JavaScript, Python, and PCRE.[^]
This site also show the Regex in a nice graph but can't test what match the RegEx: Regexper[^]
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QString testString = "([0-F]{2}[:]){5}[0-F]{2}";

My error was - what is a definition of "preceding element " ?

( )


or [] ?


here ?

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Peter_in_2780 8-Jul-22 19:00pm    
And it's still wrong. Try ::::::::::::::::: as just one example.

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