How to use regex to check if a javascript string contains a pattern
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- เผยแพร่เมื่อ 11 ก.ย. 2022
- Regex is very useful, be sure to take time to learn it.
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More regex please
YES PLEASE!!!!!!
TRUEEE!!
Regular Expressions is the only thing that can make me drop to the floor crying uncontrollably with my thumb in my mouth 😢
If a pattern is getting long and unwieldy, I recommend breaking it up into multiple tests. Just be sure to name each test descriptively so you don't forget what they each do.
😂
The g is not needed when simply testing for presence, creates a problem if you were to run the re.test again:
const text1 = "something dog5 is great";
const text2 = "cat1 foo";
const re = /[a-z]+\d/g
console.log(re.test(text1)); // true
console.log(re.test(text2)); // false
re.test(text2) should return true, but the global flag causes regex to assume that you want to check for next matches (at later index than dog5) instead of starting from the beginning
You can do some crazy stuff with your regex. Nice video
There it is again. "We use a ReGular Expression, also called ReJex"
This is how most people pronounce it. Sure, it’s odd.
Probably because it looks similar the Regedit (registry editor).
@@NickCombs wat
@@YamiSuzume it's a windows utility that's been around forever
@@NickCombs No shit, I just think that feels a bit far-fetched
love the shorts. great stuff
not a channel, but a treasure trove of useful information 🔥
First time I understand something on regex. Thanks
Good job babe!
Keep up the good content
More this please.
Regex so usefull more please
Make full regex tutorial please
Im pretty good with regexes, except for look arounds, I tend to have to always have to look up how those work again, and I think named groups is a thing, I would have to check back how they work, and some of the shortforms for any whitespace, etc.
But I am good with the . ? + * ^ […] {n,m} {n,} and {,n} symbols and the meaning of an odd vs even chain of \ and know what the /.../g g means and I think there is also /.../i i for ignorecase, and I know what greediness means.
Nice, I pretty much always dev patterns on regex101 so I have the cheat sheet and breakdown right there. You can even save and share results.
Man you broke down Regex the easiest I’ve ever seen lol. Thx
Nice ! And the red text behind each line is extension or something ?
Can you do a javascript to python comparison? like the things you can do in javascript that you can similarly do in python?
What are the extensions you use in VSCode?
🙌🙌🙌
Can you make a tutorial for RegEx please. Its so confusing
Yeah I could try to make one
@@WebDevCody Thank you so much! you explain everything so simple which is easy to understand and thanks for all your great videos!
DON'T WASTE YOUR TIME learning regex. There are websites that will write the regex patterns for you; you just tell it what you want the regex to check for and it gives you the code instantly
What’s the point of the re.test(text) and not directly re.test why wouldn’t it work?
Hello i am very cool!
Amazing! just need to know that [a-z]+ means more than one character?
The + means anything before it will appear at least once or more times
The [a-z] means any lowercase letter, the + means it can appear 1 or more times in a row.
+ is shorthand for {1,} and * is shorthand for {0,}
The "a-z" is range that is shorthand for those letters and everything between, so you can do [a-e] if you only want to match on the letters "a,b,c,d,e". If you specially want certain characters you can just include those: [rstlne] for the Wheel of Fortune letters :D
Guys, DON'T WASTE YOUR TIME learning regex expressions; they are immensely difficult to learn. There are websites that will write regex patterns for you, you just describe what you want the regex to do and it will give you the code instantly.
By describing a pattern you have effectively already made a regex. If u just don't know the symbols then may the hallucinating mind of gippidy help u.. I wouldn't trust on it... regex are already considered very fragile in prod, if u don't get them as the one putting them in then it's a disaster waiting to happen.
Of course now this regexp works only for english text, as other languages use chars outside the ASCII range a-z... 🤷♂️
In Javascript, we have to use the \u#### token to match specific unicode chars. Other coding languages include \X which match any unicode char, but with the caveat that it also matches end of line.
Also known as a "rejex" .? I thought it was a regex
how is the output show next to code while he write the code show him their error or what ever
It's a vs code extension called "Error Lens"
So, I'm (beginner?) in a programming. But why everyone uses constants everywhere?!
Well ECMA6
It"s a good principle to declare variables you know aren"t going to change as const
Actually, consts are used this often only in javascript, it's actually a good practice.
Before that, you need to learn about global and local declaration of variables and how var, let and const are used there. If you're learning JS rn, I recommend reading ES6 or 2015 documentation of JS
@@69k_gold ok, thanks! I got it!
@@69k_gold they're not only used that much in JS, low level programming languages like C++ and Rust use them a lot as well, however it's usually for different reasons, in JS, const is a guarantee that an immutable object will remain untouched, which mostly just supports the functional paradigm that JS likes and does really well, however in lower level programming it's just a promise to the compiler that we won't change the value, for instance we can guarantee that way that a function will be pure by passing a constant reference or pointer, however we're offered much more freedom, as we can always cast the const away and change the value, at the cost of hard to debug code with potential undefined behavior if you don't handle things properly.