Best of Fluent 2012: /Reg(exp){2}lained/: Demystifying Regular Expressions

From Fluent 2012:
Quick, what does this do: /(\/\*?\\/)|\/\/.*?(
?
|$)/g? If you're like many developers, you just averted your eyes, and your heart is now in your throat. Symptoms included sweaty palms and recurring nightmares with blood-thirsty ASCII symbols. But don't worry, this condition doesn't have to be chronic. A cure is right around the corner.
As with many developers, you're familiar with the power of regular expressions, but anything beyond the basics scares the crap out of you. Fear no more young padawan! In this talk, we'll start with the basics and progressively enhance your knowledge until you're coding regular expressions like a champ. Everything will be demonstrated live with visual examples that ensure maximum comprehension.
About Lea Verou
Lea works as a Developer Advocate for W3C. She has a long-standing passion for open web standards, which she fulfills by researching new ways to use them, blogging, speaking, writing, and coding popular open source projects to help fellow developers. She is a member of the CSS Working Group, which architects the language itself. Lea studied Computer Science in Athens University of Economics and Business, where she co-organized and occasionally lectured a cutting edge Web development course for 4th year undergrads. She is one of the few misfits who love code and design equally.
Produced by: Yasmina Grecp
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[@danielwatson7540]

Day 1 of RegEx: Confused...

[@VictoryChang]

Excellent talk. Found the challenges and performance tips very useful. Thanks!

[@cetti4405]

you explained this for me very well. Thank you!

[@yanistancheva3076]

Thank you so much for your talk, makes everything much clear now xx

[@kayvankazeminejad9992]

Excellent presentation. Thank you

[@TurboRSV]

Supernice! Was waiting for such simple explanation to RegEx!

[@VictorRivas_vctr]

HUGE THANK YOU YOU'VE EARNED A NEW FAN! JUST AMAZING!!

[@bonduu01]

Making sense of writing a REGEX for a n application log with complex data pattern for Fluentd brought me here, and I was not disappointed...great video!

[@haalin5359]

This is great tutorial very clear and easy to follow. Thanks for sharing!!!

[@uhoh007]

Tour de force. Wonderful, imspiring presentation. Thank You!

[@cristianAndrs]

Lea talks so clear i can understand every single word. This is an excelent conference.

[@gherbihicham8506]

Very good reviewing material, and a very good presenter if i do say so myself.

[@SolihullRog]

This is absolutely mind-boggling. The sequence of the speech, coupled with the associated Playground site, demonstrate exactly how to get a message across. Currently 3.1k thumbs up and 53 thumbs down. That doesn't do it justice.

[@FlashManinSpace]

Best video on regular expression ever!

[@sherylbee8634]

😂 you're my hero!!

[@HugoPineda83]

This video is so helpful. Lea is a great speaker!!

[@DanMaxmusic]

Very good. Was really stuck on Reg Exp, but this really helped. Thanks a lot:)

[@AnthonyDev]

Nowadays this would be called "the regexp crash course". Thanks. 😊

[@jasusyb2734]

Thx for your talk!

[@hydtechietalks3607]

ORIELLY is THE BEST in books, even talks after this...Hats OFF!!

[@rahmantanvir99]

Best regular expression tutorial,i have ever found......

[@TaSwavo]

This is now on my Fav Bar - could tell a bit nervous but she great - best tech youtube from a non-mouthpiece but a genuine techy (don't care about eloquence or charisma (I'm not listening to an Apple pitch for a new product) - give me what I need to know - she did). Great. Really good. Thanks O'Reilly. Thanks Lea - had to go back to find the name.

[@CarryShout91]

great presentation! very clear and useful :)

[@eniac78]

Like that she notes it's usefulness for more than just coding. I use as much to search and do find and replace in my code solutions as I do in actual coding.

[@raditz2488]

6:17 a subtle note on greediness of regex, It wants to match one or none a with as much content it can traverse, so ti traverses to the last a and picks that as a match. 7:45 Reversing greediness by using '?' after a quantifier(note: \w now supports unicode as well in re engines, to revert back to old only ascii aware mode enable /a flag.) 12:52 Counting words in a string. 20:18 Grouping with paranthesis. 20:22 Capture effect of paranthesis. 21:29 Disabling capturing by groups. 27:54 Trimming a string. 31:33 Lookahead

[@evgenylevchenya8734]

Very clean. Thanks

[@hassanawodi5888]

For someone with basic idea about regular expression, this is really really cool. Well explained! A total noobs may struggle though. The O'Reilly book on regex comes in handy for a total noobs.

[@efi13efi]

Thanks Lea!

[@jiyeesheng8968]

Great talks. much pratical.

[@georgigeorgiev2219]

It is useful lesson for regex. Thank you. GOD bless you.

[@joebazooks]

one of the best regex vids I've seen. just wish it was a bit more thorough

[@RonaldsGailis]

Great talk!

[@vahidrajaei4095]

Awesome :) very well done

[@doug65536]

Very nice work.

[@devonhorner1516]

Great presentation and app (save the minor bug). Very motivating for me to improve my regex skills

[@GanpatKakar]

Thank you dear for such a valuable knowledge, which saved me from failing into an interview.

[@johnnycas1]

Great class!!!!!!! Thanks!!!

[@engelshentenawy]

if you get the talk , you will get the title /Reg(exp){2}lained/ smart.

[@DaNa-px7ol]

isn´t there a "p" to much?

[@farhanaditya2647]

"Regexpexp" or "ained". Still don't get it.

[@beardymonger]

Excellent presentation!!!! Few remarks: 1) pronunciation of integer 2) in some of the exercises the solution depended on tools discussed later

[@AaronStagl]

Absolutely loved the hex colors!

[@Taneth]

I call it "wildcards on steroids". It's one of my favourite tools.

[@bogdanpintican]

Thank you!

[@lheynlin4107]

I liked, because showed more than we usually see about regex, very good, I think.

[@jthid]

awesome, thanks

[@Donevigor]

Nice lecture! The false positives photo gave me a lough :).

[@c0mpuipf]

love the swallowing sounds

[@jtillery]

I always find Lea Verou presentations interesting. She talks a little fast, but still very easy to understand.

[@LARathbone]

Great presentation and the slide deck blew me away. Can I hire this person to do my decks?

[@AjinkyaBorade]

Lea Verou to the rescue :) Love ur simple explanations, u made tedious RegEx easy #javascript

[@jbucata]

This talk is like drinking from a firehose! It's good material and it's a useful and quick review if you've seen much of this before. But I've got people who are trying to learn programming who haven't ever seen a regex before... this would totally overwhelm them. A gentler introduction would be much better for them. But, for what it is, it's quite good.

[@jbucata]

Well I guess that's true. If you know if any such gentle introductions, please do share. (BTW I'm already fluent in regexes myself, I'm just on the lookout for materials to teach them to others.)

[@jdeveloper777]

Jason, yes you're right about the firehose. However, what I did is to read the Java SE 8 tutorial on regular expressions and watch the relevant parts of Lea's presentation (this video). I divided this method over several days, perhaps 10 days, only focusing on one concept at a time. That way, I was able to easily follow along and learn.

[@kbcarte420]

ascii puke, lol never heard that before.

[@leguminosa9]

love her

[@uthappakc3073]

This is great if you are looking for something brief.

[@adityapasari2548]

This is gold

[@drakezen]

Awesome

[@WilsonMar1]

In this video Lea Verou dives into what many developers fear - Regular Expressions. [01:57] into this kzbin.info/www/bejne/e5zPpniJbrepl80 the URL that works is leaverou.github.io/regexplained/ from source at github.com/LeaVerou/regexplained which is an amazing web app shown in the video.

[@shantanuborgohain8331]

30:42 Legend has it she got arrested after that talk.

[@laughingalien]

Nicely spotted, sir. Now I really love her.

[@climaxcontoseroticos7682]

How do you name a person who is good looking and saves your life?

[@DurgaswaroopPerla]

+Clímax Contos Eróticos 'Lea Verou' would be the word(s) you're looking for :D

[@williamkingston4278]

+Durga swaroop Perla XD But what if her voice just makes me wanna kill myself

[@igrewold]

pretty pretty ;D BTW I came across this video when I was looking for Automata online lessons!

[@devinelder1203]

This video has no sound =(. All other youtube videos played simultaneously work just fine. I ended up using the subtitles, but it was very inconvenient. Otherwise, an amazing and thorough video.

[@RemkoRoodselaar]

Finally found that password validation expression!

[@davisdoesgamesreal]

11:07 welcome to programming class, you've been here for as long as you can remember. mewo: meow (waiting for a regex lecture to happen?)

[@Skatox]

Si alguien quiere aprender sobre expresiones regulares, este video lo explica todo en 1 hora.

[@AZ-rg3rf]

Yo comprendo todos ahora

[@TrustNoOneEverEver]

She AVOIDed eyecontact during the whole talk.

[@achharsh]

thanks a lot..

[@xaviercombelle4316]

nice talk

[@StefanRitterOLD]

nice!

[@syedkhaleelmyprofile]

very usefull.

[@RajaSekharBusapalli999]

I love You.... This is very simple... the web base provides u very easy cross-verification.... its amazing and u teach awesome. u look awesome too....

[@zezeandjr4110]

Ooh, love that "Z" Zedd.

[@jumpieva]

I actually would think this would have been a cringeworthy thing to try to lecture, but it was pretty good. However, it was just so fast I had to redo a few things.

[@SandyRocks007]

One silly doubt is this concept same for regular expression used in any language ??? like Java etc ??

[@mahmoudzakria6946]

I would ask about "Quantifiers" What are they useful for excatly? I think they are nothing except searching in string like this "caaaaat".

[@HartleySan]

Lea Verou is awesome and her presentation looks beautiful, but for someone learning regexes for the first time, this is way too much, too fast.

[@hansf14]

@39:26 it gives wrong result when it's 50. Thank you for the great lecture though.

[@Rattus1]

2:10 dying for the oreilly regex book

[@SamiullahKhan]

?: to avoid remembering the match isn't working for me in JavaScript. Not matter the variables are remembered when I access them using $1 or $2

[@jimtonykiller]

Samiullah Khan you are the only one seriously studying here

[@SamiullahKhan]

Haha looks like I was really involved in this talk and it made learning of Regular Expression really easy for me.

[@joydeeproy87]

can anyone help me where this 21:43 test link is?

[@dancorvalan3205]

Is there some sort of regular expression for audio processing where we could specify and therefore have removed every "ahhhh.." she does throughout the entire video? (Please!)

[@AllSeasonsVideo]

That is exactly why developers hate regex. It's hard to learn. This was the absolute most basic way one could explain regex.

[@youssefbelmeskine8059]

شكرا لك على هدا الشرح الرائع وكذالك على الموقع المثالي في اختبار regex

[@NabeelMolham]

Really good into for #RegularExpressions #js #php #programminglanguages

[@SimonBohlin]

11:56 oh noes, please don't put - in the middle of [] because someone is going to create a bug from that.

[@fdmazlum]

They forgot the i variable for the hexcode..

[@asmartbajan]

Really good tutorial. Btw, the "g" in "integer" is followed by an "e". So, it's pronounced somewhat like the "j" in "jam" and not like the "g" in "grammar". (Of course, with English there are always exceptions to the rule but the pronunciation of "integer" follows the rule.)

[@AnoopD2013]

+Wayne Phillips She is from Greece ....... :)

[@ParantapSharma]

919 likes on 3 dislikes... that ought to be something good. i saw such good ratios only on Bhagat Singh videos before

[@ko95]

neat

[@notdaveschannel9843]

This is the woman who wrote Prism.js.

[@JulesManson]

My God she is as beautiful as she is brainy. I think I am in love.

[@Vlad-1986]

He, I think I'll stick to ANSI C#

[@saandesh32]

this was in 2012 .. it's 2019 now ...

[@SycamoreGlitch]

this was in 2019 .. it's 2020 now ...

[@kkikki-jd9uo]

she seems faster than regex.....please dont mind..

[@coderwelsch]

Loving her... :D

[@Shmack_]

This girl has the best talks and sexy voice and look!!!

[@rougearlequin]

Do most languages use the same standard for regexp?

[@farhanaditya2647]

yes

[@coffeebutch]

why most people are scared of Regex.. Apparently I am too. Watching tutorials are like 'Oh yup I got it.'. When doing it myself is like ..'urrhh...i guess i should watch more tutorials.'

[@CUN006]

The UI looks awesome! Can someone tell me what software or website is she using?

[@michaelthelen1]

+CUN006 leaverou.github.io/regexplained/

[@CUN006]

+Michael Thelen OMG that saves my life! May I ask how did you find it in the first place?

[@michaelthelen1]

+CUN006 luck. Was clicking all her links, checked out her github, happened to open the README. :D

[@CUN006]

+Michael Thelen Way to go man!

[@CUN006]

Kile Maximum All right found it. Thx

[@KipIngram]

What a tremendously appealing young lady. :-)

[@jukkrityotha8230]

other by thailand 19:25 21-4-2019

[@steffenlaurens8280]

This video makes me dizzy, is there any cheatsheet available out there?

[@ahmedzulu1435]

cmd + t, "regex cheatsheet", enter -> first result; would have used less time and characters then writing this comment...

[@ZekonjaPekonja]

that neurotic drinking...

[@ballercat]

For sure walk away from the mic when eating/drinking. Couldn't make it through the video.

[@doodoostickstain]

that considered, i'm impressed you made it to the comments section, where more annoying things commonly occur. usually lots of contributors in that regard *cough* >_>

[@ballercat]

Well yeah... Wouldn't you wanted to check if someone else reacted the same way? Not really that impressive. Besides I din't think the video had poor content, just that the gulping of water into the mic was super unpleasant. Obviously I wasn't the only one /shrug