Develop Reference

Getting element from filename using continous split or regex

I currently have the following string :
AAAAA/BBBBB/1565079415419-1564416946615-file-test.dsv
But I would like to split it to only get the following result (removing all tree directories + removing timestamp before the file):
1564416946615-file-test.dsv
I currently have the following code, but it's not working when the filename itselfs contains a '-' like in the example.
getFilename(str){
return(str.split('\\').pop().split('/').pop().split('-')[1]);
}
I don't want to use a loop for performances considerations (I may have lots of files to work with...) So it there an other solution (maybe regex ?)

We can try doing a regex replacement with the following pattern:
.*\/\d+-\b
Replacing the match with empty string should leave you with the result you want.
var filename = "AAAAA/BBBBB/1565079415419-1564416946615-file-test.dsv";
var output = filename.replace(/.*\/\d+-\b/, "");
console.log(output);
The pattern works by using .*/ to first consume everything up, and including, the final path separator. Then, \d+- consumes the timestamp as well as the dash that follows, leaving only the portion you want.

You may use this regex and get captured group #1:
/[^\/-]+-(.+)$/
RegEx Demo
RegEx Details:
[^\/-]+: Match any character that is not / and not -
-: Match literal -
(.+): Match 1+ of any characters
$: End
Code:
var filename = "AAAAA/BBBBB/1565079415419-1564416946615-file-test.dsv";
var m = filename.match(/[^\/-]+-(.+)$/);
console.log(m[1]);
//=> 1564416946615-file-test.dsv

How would I write a Regular Expression to capture the value between Last Slash and Query String?

Problem:
Extract image file name from CDN address similar to the following:
https://cdnstorage.api.com/v0/b/my-app.com/o/photo%2FB%_2.jpeg?alt=media&token=4e32-a1a2-c48e6c91a2ba
Two-stage Solution:
I am using two regular expressions to retrieve the file name:
var postLastSlashRegEx = /[^\/]+$/,
preQueryRegEx = /^([^?]+)/;
var fileFromURL = urlString.match(postLastSlashRegEx)[0].match(preQueryRegEx)[0];
// fileFromURL = "photo%2FB%_2.jpeg"
Question:
Is there a way I can combine both regular expressions?
I've tried using capture groups, but haven't been able to produce a working solution.

From my comment
You can use a lookahead to find the "?" and use [^/] to match any non-slash characters.
/[^/]+(?=\?)/
To remove the dependency on the URL needing a "?", you can make the lookahead match a question mark or the end of line indicator (represented by $), but make sure the first glob is non-greedy.
/[^/]+?(?=\?|$)/

You don't have to use regex, you can just use split and substr.
var str = "https://cdnstorage.api.com/v0/b/my-app.com/o/photo%2FB%_2.jpeg?alt=media&token=4e32-a1a2-c48e6c91a2ba".split("?")[0];
var fileName = temp.substr(temp.lastIndexOf('/')+1);
but if regex is important to you, then:
str.match(/[^?]*\/([^?]+)/)[1]

The code using the substring method would look like the following -
var fileFromURL = urlString.substring(urlString.lastIndexOf('/') + 1, urlString.lastIndexOf('?'))

parsing image name from img tag with regex

I have an <img> tag inside a div where i want to get the image name through javascript and regex.
Now, I successfully retrieved the <img> tag as a string.
var bigImage = $(this).find('.img-container img')
var bigImageSrc = bigImage[0].src
var regx = /g\bplaceholderdefault\.jpg?\b/g
var match = bigImageSrc.match(regx)
I want this expression to see if there is placeholderdefault.jpg in the string.
By the way, bigImageSrc returns a valid string, as I checked it with typeof
Now the problem is it returns null even if bigImageSrc's value is http://localhost/yogurtbar/images/slider/placeholderdefault.jpg
I don't get why it doesn't detect placeholderdefault.jpg in the string. I tried (and produced) this regular expression in Regexr and it works.
What am I doing wrong in my code?

There is no need of regex.\
You can use indexOf. This will run faster as compared to regex:
if (bigImageSrc.indexOf('placeholderdefault.jpg') > -1) {
// Present
If you want to check it with regex:
if (/placeholderdefault\.jpg/.test(bigImageSrc)) {
// Present
}
You need to escape .

You need to remove the g present at the start.
var regx = /g\bplaceholderdefault\.jpg?\b/g;
^
|
Since there isn't a charcater g exists before p (in placeholder), your regex fails to find a match.
correct one would be,
var regx = /\bplaceholderdefault\.jpg?\b/g;
and also, I think you want to match both jpg and jpeg formats.
var regx = /\bplaceholderdefault\.jpe?g\b/g;

Easy way will be to get the image name using split()
var bigImageSrc = 'http://localhost/yogurtbar/images/slider/placeholder-default.jpg';
var filename = bigImageSrc.split("/").pop();
console.log(filename);
//output placeholder-default.jpg

How to find in javascript with regular expression string from url?

Good evening, How can I find in javascript with regular expression string from url address for example i have url: http://www.odsavacky.cz/blog/wpcproduct/mikronebulizer/ and I need only string between last slashes (/ /) http://something.cz/something/string/ in this example word that i need is mikronebulizer. Thank you very much for you help.

You could use a regex match with a group.
Use this:
/([\w\-]+)\/$/.exec("http://www.odsavacky.cz/blog/wpcproduct/mikronebulizer/")[1];
Here's a jsfiddle showing it in action
This part: ([\w\-]+)
Means at least 1 or more of the set of alphanumeric, underscore and hyphen and use it as the first match group.
Followed by a /
And then finally the: $
Which means the line should end with this
The .exec() returns an array where the first value is the full match (IE: "mikronebulizer/") and then each match group after that.
So .exec()[1] returns your value: mikronebulizer

Simply:
url.match(/([^\/]*)\/$/);
Should do it.
If you want to match (optionally) without a trailing slash, use:
url.match(/([^\/]*)\/?$/);
See it in action here: http://regex101.com/r/cL3qG3

If you have the url provided, then you can do it this way:
var url = 'http://www.odsavacky.cz/blog/wpcproduct/mikronebulizer/';
var urlsplit = url.split('/');
var urlEnd = urlsplit[urlsplit.length- (urlsplit[urlsplit.length-1] == '' ? 2 : 1)];
This will match either everything after the last slash, if there's any content there, and otherwise, it will match the part between the second-last and the last slash.

Something else to consider - yes a pure RegEx approach might be easier (heck, and faster), but I wanted to include this simply to point out window.location.pathName.
function getLast(){
// Strip trailing slash if present
var path = window.location.pathname.replace(/\/$?/, '');
return path.split('/').pop();
}

Alternatively you could get using split:
var pieces = "http://www.odsavacky.cz/blog/wpcproduct/mikronebulizer/".split("/");
var lastSegment = pieces[pieces.length - 2];
// lastSegment == mikronebulizer

var url = 'http://www.odsavacky.cz/blog/wpcproduct/mikronebulizer/';
if (url.slice(-1)=="/") {
url = url.substr(0,url.length-1);
}
var lastSegment = url.split('/').pop();
document.write(lastSegment+"<br>");

Regex: Getting content from URL

I want to get "the-game" using regex from URLs like
http://www.somesite.com.domain.webdev.domain.com/en/the-game/another-one/another-one/another-one/
http://www.somesite.com.domain.webdev.domain.com/en/the-game/another-one/another-one/
http://www.somesite.com.domain.webdev.domain.com/en/the-game/another-one/

What parts of the URL could vary and what parts are constant? The following regex will always match whatever is in the slashes following "/en/" - the-game in your example.
(?<=/en/).*?(?=/)
This one will match the contents of the 2nd set of slashes of any URL containing "webdev", assuming the first set of slashes contains a 2 or 3 character language code.
(?<=.*?webdev.*?/.{2,3}/).*?(?=/)
Hopefully you can tweak these examples to accomplish what you're looking for.

var myregexp = /^(?:[^\/]*\/){4}([^\/]+)/;
var match = myregexp.exec(subject);
if (match != null) {
result = match[1];
} else {
result = "";
}
matches whatever lies between the fourth and fifth slash and stores the result in the variable result.

You probably should use some kind of url parsing library rather than resorting to using regex.
In python:
from urlparse import urlparse
url = urlparse('http://www.somesite.com.domain.webdev.domain.com/en/the-game/another-one/another-one/another-one/')
print url.path
Which would yield:
/en/the-game/another-one/another-one/another-one/
From there, you can do simple things like stripping /en/ from the beginning of the path. Otherwise, you're bound to do something wrong with a regular expression. Don't reinvent the wheel!