cut expression from specific character with javascript - javascript

I am having an application where the user gives a email. For each user on directory is created on my server. I would like the name of the directory to be based on the email of the user, but I can't use directly the email. What I would like is to modify the email to make it a appropritate directory . For example if I have: name.lastname#test.com, I wouls like to create the string namelastname. How can I do that with javascript.
Thanks!

Try this, split replace and trim.
var email = "name.lastname#test.com";
var str = email.split("#")[0].replace(".","").trim();
What's actually happening here is:
email.split("#") - This will use the # character as a delimiter and split the entire string everywhere the # char appears. In this example it will yield 2 elements:
[ 'name.lastname', 'test.com' ]
Note that the delimiter character is not returned in these results.
We only need to be concerned with the text before the #, so we access the first element in the result: email.split("#")[0]
Now we use the replace function to swap specific characters. In this case we are swapping the . character for an empty string "", ie: remove it.
The trim command removes excess whitespace that might be left over.
What we are left with is the desired namelastname string.
References:
split()
replace()
trim()

Related

What Regex would capture both the beginning and end from of a string?

I am trying to edit a DateTime string in typescript file.
The string in question is 02T13:18:43.000Z.
I want to trim the first three characters including the letter T from the beginning of a string AND also all 5 characters from the end of the string, that is Z000., including the dot character. Essentialy I want the result to look like this: 13:18:43.
From what I found the following pattern (^(.*?)T) can accomplish only the first part of the trim I require, that leaves the initial result like this: 13:18:43.000Z.
What kind of Regex pattern must I use to include the second part of the trim I have mentioned? I have tried to include the following block in the same pattern (Z000.)$ but of course it failed.
Thanks.
Any help would be appreciated.
There is no need to use regular expression in order to achieve that. You can simply use:
let value = '02T13:18:43.000Z';
let newValue = value.slice(3, -5);
console.log(newValue);
it will return 13:18:43, assumming that your string will always have the same pattern. According to the documentation slice method will substring from beginIndex to endIndex. endIndex is optional.
as I see you only need regex solution so does this pattern work?
(\d{2}:)+\d{2} or simply \d{2}:\d{2}:\d{2}
it searches much times for digit-digit-doubleDot combos and digit-digit-doubleDot at the end
the only disadvange is that it doesn't check whether say there are no minutes>59 and etc.
The main reason why I didn't include checking just because I kept in mind that you get your dates from sources where data that are stored are already valid, ex. database.
Solution
This should suffice to remove both the prefix from beginning to T and postfix from . to end:
/^.*T|\..*$/g
console.log(new Date().toISOString().replace(/^.*T|\..*$/g, ''))
See the visualization on debuggex
Explanation
The section ^.*T removes all characters up to and including the last encountered T in the string.
The section \..*$ removes all characters from the first encountered . to the end of the string.
The | in between coupled with the global g flag allows the regular expression to match both sections in the string, allowing .replace(..., '') to trim both simultaneously.

Regex javascript to only return a value and not full match

How do we do look behind in java script like we can in java or php?
RegEx works for php parser using lookbehind
Here is the working Regex using php parser.
(?<=MakeName=)(.*?)([^\s]+)
This produces the value
(MakeName=)(.*?)([^\s]+)
this produces the match + value
xml response to extract value from.
<ModelName="Tacoma" MakeName="Tundra" Year="2015">
I just need the value
There is no look-behind in JavaScript.
If you are sure the attribute MakeName is present in the input, then you could use this regular expression:
/[^"]*(?!.*\sMakeName\s*=)(?="([^"]*"[^"]*")*[^"]*$)/
It grabs the first series of characters that do not contain a double quote and have a double quote immediately following it, with an even number of double quotes following after that until the end of the input (to make sure we are matching inside a quoted string), but MakeName= should not occur anywhere after the match.
This is of course still not bullet proof, as it will fail for some boundary cases, like with single quoted values.:
<ModelName="Tacoma" MakeName='Tundra' Year="2015">
You could resolve that, if needed, by repeating the same pattern, but then based on single quotes, and combining the two with an OR (|).
Demo:
var s = '<ModelName="Tacoma" MakeName="Tundra" Year="2015">';
result = s.match(/[^"]*(?!.*\sMakeName\s*=)(?="([^"]*"[^"]*")*[^"]*$)/);
console.log(result[0]);

Javascript Regex: match text after pattern

I have text of a form where there are paragraphs of text with urls interspersed.
I would like to parse the string creating html links from the urls and using the following text as the descriptive link text i.e.
possibly some text here http://www.somewebsite.com/some/path/somepage.html descriptive text which may or may not be present
into
descriptive text which may or may not be present
This SO article, JS: Find URLs in Text, Make Links, is relevant to what I'm attempting to do but simply places the url as the text within the anchor element.
I am successfully matching the url with
var urlRE= new RegExp("([a-zA-Z0-9]+://)?([a-zA-Z0-9_]+:[a-zA-Z0-9_]+#)?([a-zA-Z0-9.-]+\\.[A-Za-z]{2,4})(:[0-9]+)?([^ ])+");
but am unsure how to perform the match afterwards.
I came across this post Regex - Matching text AFTER certain characters which seems applicable. I've attempted to wrap my RE in /(?<=my url pattern here).+/ but get an error stating that there is an invalid group and that this results in an invalid RE.
In that post J-Law mentions that
Variable-length lookbehinds aren’t allowed
Is this what I'm attempting to do?
Since I'm already matching the url I feel like I could easily do some substring math to get the desired results.
I'm just using this as an attempt to learn more about regex.
Thanks
Just add another capturing group to capture all the stuff at the end and make your inner groups non-capturing. Something like:
var urlRE= new RegExp("((?:[a-zA-Z0-9]+://)?(?:[a-zA-Z0-9_]+:[a-zA-Z0-9_]+#)?(?:[a-zA-Z0-9.-]+\\.[A-Za-z]{2,4})(?::[0-9]+)?(?:[^ ])+)(.*)$");
var s = "possibly some text here http://www.somewebsite.com/some/path/somepage.html descriptive text which may or may not be present"
var match = urlRE.exec(s);
alert(match[0] + "\n\n" + match[1] + "\n\n" + match[2]);
// Returns:
// ["http://www.somewebsite.com/some/path/somepage.html descriptive text which may or may not be present",
// "http://www.somewebsite.com/some/path/somepage.html",
// " descriptive text which may or may not be present"]
I wrapped your entire regex in brackets () to form the first capturing group and inside that I made all your existing groups non-capturing with ?:, You don't absolutely need to do that (making them non-capturing), but it does simplify the output. Then I just added one more group (.*) to capture everything else until the end of the string $.
After .exec if you have a match, your match will be in [0], the url part will be in [1] and the rest of your text in [2]. This is why we used the non-capturing groups because otherwise you'd have a bunch of other captures that may or may not be useful.

string match in javascript with special Characters

Hope you all are doing good,
Here is my problem ,I wanted to split a string writing some code like
var searchingWords='Hi # All "SO Members"';
var searchTextList=searchingWords.match(/\w+|"[^"]+"/g);
what it does is it returns an array which is separated by blank space , double quotes so I get the value of array like
["Hi","All","\"SO Members\""] but special characters '#' is missing ( characters could be &,* etc), so I need required regular exp which will be pass to match function or is there other way to do it in javascript?
Please check the sample here
Thanks.

replace similar string in a text using javascript regex

we have a text like:
this is a test :rep more text more more :rep2 another text text qweqweqwe.
or
this is a test :rep:rep2 more text more more :rep2:rep another text text qweqweqwe. (without space)
we should replace :rep with TEXT1 and :rep2 with TEXT2.
problem:
when try to replace using something like:
rgobj = new RegExp(":rep","gi");
txt = txt.replace(rgobj,"TEXT1");
rgobj = new RegExp(":rep2","gi");
txt = txt.replace(rgobj,"TEXT2");
we get TEXT1 in both of them because :rep2 is similar with :rep and :rep proccess sooner.
If you require that :rep always end with a word boundary, make it explicit in the regex:
new RegExp(":rep\\b","gi");
(If you don't require a word boundary, you can't distinguish what is meant by "hello I got :rep24 eggs" -- is that :rep, :rep2, or :rep24?)
EDIT:
Based on the new information that the match strings are provided by the user, the best solution is to sort the match strings by length and perform the replacements in that order. That way the longest strings get replaced first, eliminating the risk that the beginning of a long string will be partially replaced by a shorter substring match included in that long string. Thus, :replongeststr is replaced before :replong which is replaced before :rep .
If your data is always consistent, replace :rep2 before :rep.
Otherwise, you could search for :rep\s, searching for the space after the keyword. Just make sure you replace the space as well.

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