Javascript trim double slashes - javascript

I would like to trim //a/url/// to a/url. There are a few questions on Stackoverflow but they don't work, solves another problem or is too long and complex.
The code below is working and is based on Javascript regular expression: remove first and last slash
function trimSlashes(str) {
str = str.replace(/^\/|\/$/g, '');
return str.replace(/^\/|\/$/g, '');
};
However it's not very nice to duplicate code like that. How would a regex look like that takes care of double slashes as well?
Testcase
let str1 = trimSlashes('/some/url/here/');
let str2 = trimSlashes('//some/other/url/here///');
Expected result
some/url/here
some/other/url/here
Wishlist
Just a single regex
Shorter or faster is better

Here's another variation without a regex but with a functional flair. I don't know about the performance but I had fun writing it and seems less cryptic.
const newString = '//some/other/url/here///'
.split('/')
.filter(s => s)
.join('/')
Edit:
Just ran some perf tests and this is slower than a regex but it might be insignificant if used sparingly.
https://jsperf.com/regex-vs-functional/1

replace(/^\/+|\/+$/g, '') is what you're looking for:
Result with both test cases:
> '/some/url/here/'.replace(/^\/+|\/+$/g, '');
"some/url/here"
> '//some/other/url/here///'.replace(/^\/+|\/+$/g, '');
"some/other/url/here"
Explained:
^\/+ # one or more forward slashes at the beginning
| # or
\/+$ # one or more forward slashes at the end

With regexes you must be careful of unintended matches. for example do you want to trim the slash when the text is "// and this is a comment in some line of text//"?
If you don't want to trim things like that down you need to be a little more careful with the regex, how about this?
let regex = /^\/+([\w\/]+?)\/+$/;
let matches = regex.exec("//some/other/url/here///");
let url = matches[1];
https://regex101.com/r/K8CnxP/1

Related

Regex, separate by comma, javascript

My string:
AA,$,DESCRIPTION(Sink, clinical),$
Wanted matches:
AA
$
DESCRIPTION(Sink, clinical)
$
My regex sofar:
\+d|[\w$:0-9`<>=&;?\|\!\#\+\%\-\s\*\(\)\.ÅÄÖåäö]+
This gives
AA
$
DESCRIPTION(Sink
clinical)
I want to keep matches between ()
https://regex101.com/r/MqFUmk/3
Here's my attempt at the regex
\+d|[\w$:0-9`<>=&;?\|\!\#\+\%\-\s\*\.ÅÄÖåäö]+(\(.+\))?
I removed the parentheses from within the [ ] characters, and allowed capture elsewhere. It seems to satisfy the regex101 link you posted.
Depending on how arbitrary your input is, this regex might not be suitable for more complex strings.
Alternatively, here's an answer which could be more robust than mine, but may only work in Ruby.
((?>[^,(]+|(\((?>[^()]+|\g<-1>)*\)))+)
That one seems to work for me?
([^,\(\)]*(?:\([^\(\)]*\))?[^,\(\)]*)(?:,|$)
https://regex101.com/r/hLyJm5/2
Hope this helps!
Personally, I would first replace all commas within parentheses () with a character that will never occur (in my case I used # since I don't see it within your inclusions) and then I would split them by commas to keep it sweet and simple.
myStr = "AA,$,DESCRIPTION(Sink, clinical),$"; //Initial string
myStr = myStr.replace(/(\([^,]+),([^\)]+\))/g, "$1#$2"); //Replace , within parentheses with #
myArr = myStr.split(',').map(function(s) { return s.replace('#', ','); }); //Split string on ,
//myArr -> ["AA","$","DESCRIPTION(Sink, clinical)","$"]
optionally, if you're using ES6, you can change that last line to:
myArr = myStr.split(',').map(s => s.replace('#', ',')); //Yay Arrow Functions!
Note: If you have nested parentheses, this answer will need a modification
At last take an aproximation of what you need:
\w+(?:\(.*\))|\w+|\$
https://regex101.com/r/MqFUmk/4

Regex to get the text between two characters?

I want to replace a text after a forward slash and before a end parantheses excluding the characters.
My text:
<h3>notThisText/IWantToReplaceThis)<h3>
$('h3').text($('h3').text().replace(regEx, 'textReplaced'));
Wanted result after replace:
notThisText/textReplaced)
I have tried
regex = /([^\/]+$)+/ //replaces the parantheses as well
regex = \/([^\)]+) //replaces the slash as well
but as you can see in my comments neither of these excludes both the slash and the end parantheses. Can someone help?
A pattern like /(?<=\/)[^)]+(?=\))/ won't work in JS as its regex engine does not support a lookbehind construct. So, you should use one of the following solutions:
s.replace(/(\/)[^)]+(\))/, '$1textReplaced$2')
s.replace(/(\/)[^)]+(?=\))/, '$1textReplaced')
s.replace(/(\/)[^)]+/, '$1textReplaced')
s.replace(/\/[^)]+\)/, '/textReplaced)')
The (...) forms a capturing group that can be referenced to with $ + number, a backreference, from the replacement pattern. The first solution is consuming / and ), and puts them into capturing groups. If you need to match consecutive, overlapping matches, use the second solution (s.replace(/(\/)[^)]+(?=\))/, '$1textReplaced')). If the ) is not required at the end, the third solution (replace(/(\/)[^)]+/, '$1textReplaced')) will do. The last solution (s.replace(/\/[^)]+\)/, '/textReplaced)')) will work if the / and ) are static values known beforehand.
You can use str.split('/')
var text = 'notThisText/IWantToReplaceThis';
var splited = text.split('/');
splited[1] = 'yourDesireText';
var output = splited.join('/');
console.log(output);
Try Following: In your case startChar='/', endChar = ')', origString=$('h3').text()
function customReplace(startChar, endChar, origString, replaceWith){
var strArray = origString.split(startChar);
return strArray[0] + startChar + replaceWith + endChar;
}
First of all, you didn't define clearly what is the format of the text which you want to replace and the non-replacement part. For example,
Does notThisText contain any slash /?
Does IWantToReplaceThis contain any parentheses )?
Since there are too many uncertainties, the answer here only shows up the pattern exactly matches your example:
yourText.replace(/(\/).*?(\))/g, '$1textReplaced$2')
var text = "notThisText/IWantToReplaceThis";
text = text.replace(/\/.*/, "/whatever");
output : "notThisText/whatever"`

I want to find numbers-include dot and comma- but Regex not working in javascript

I thought it was very simple to find out. But how many ways I tried still not work properly.
Below is the test snippet.
"100$ and 1.000,000EUR 1,00.0.000USD .90000000000000000000$ (09898)".replace(/[\.,\d]*/g, '{n}')
And I want the result like below.
{n}$ and {n}EUR {n}USD {n}$ ({n})
The * is your problem, change the regex to /[.,\d]+/g instead.
"100$ and 1.000,000EUR 1,00.0.000USD .90000000000000000000$ (09898)".replace(/[.,\d]+/g, '{n}');
Output
{n}$ and {n}EUR {n}USD {n}$ ({n})
JSFiddle Example Check console screen for the output.
The problem here is that [\.,\d]* can match an empty string. The first step would be to use [.,\d]+ so that at least one of these characters matches.
But a better regex would be \d[.,\d]* because it ensures the replaced characters begin with a digit, so it won't replace periods in sentences.
If you want to go further, you can also use (?=[.,\d]*\d)[.,\d]+ if to handle numbers starting with periods. This one would be the proper answer for your case. The lookahead ensures there's at least one digit anywhere in the replaced text.
Note that you don't need to escape the . inside a character class.
\.?\d[^\s]*\d
Try this.Replace with {n}.See demo.
http://regex101.com/r/kP8uF5/3
var re = /\.?\d[^\s]*\d/gm;
var str = '100$ and 1.000,000EUR 1,00.0.000USD .90000000000000000000$ (09898)';
var subst = '{n}';
var result = str.replace(re, subst);

Regex trying to match characters before and after symbol

I'm trying to match characters before and after a symbol, in a string.
string: budgets-closed
To match the characters before the sign -, I do: ^[a-z]+
And to match the other characters, I try: \-(\w+) but, the problem is that my result is: -closed instead of closed.
Any ideas, how to fix it?
Update
This is the piece of code, where I was trying to apply the regex http://jsfiddle.net/trDFh/1/
I repeat: It's not that I don't want to use split; it's just I was really curious, and wanted to see, how can it be done the regex way. Hacking into things spirit
Update2
Well, using substring is a solution as well: http://jsfiddle.net/trDFh/2/ and is the one I chosed to use, since the if in question, is actually an else if in a more complex if syntax, and the chosen solutions seems to be the most fitted for now.
Use exec():
var result=/([^-]+)-([^-]+)/.exec(string);
result is an array, with result[1] being the first captured string and result[2] being the second captured string.
Live demo: http://jsfiddle.net/Pqntk/
I think you'll have to match that. You can use grouping to get what you need, though.
var str = 'budgets-closed';
var matches = str.match( /([a-z]+)-([a-z]+)/ );
var before = matches[1];
var after = matches[2];
For that specific string, you could also use
var str = 'budgets-closed';
var before = str.match( /^\b[a-z]+/ )[0];
var after = str.match( /\b[a-z]+$/ )[0];
I'm sure there are better ways, but the above methods do work.
If the symbol is specifically -, then this should work:
\b([^-]+)-([^-]+)\b
You match a boundry, any "not -" characters, a - and then more "not -" characters until the next word boundry.
Also, there is no need to escape a hyphen, it only holds special properties when between two other characters inside a character class.
edit: And here is a jsfiddle that demonstrates it does work.

Javascript regex expression to replace multiple strings?

I've a string done like this: "http://something.org/dom/My_happy_dog_%28is%29cool!"
How can I remove all the initial domain, the multiple underscore and the percentage stuff?
For now I'm just doing some multiple replace, like
str = str.replace("http://something.org/dom/","");
str = str.replace("_%28"," ");
and go on, but it's really ugly.. any help?
Thanks!
EDIT:
the exact input would be "My happy dog is cool!" so I would like to get rid of the initial address and remove the underscores and percentage and put the spaces in the right place!
The problem is that trying to put a regex on Chrome "something goes wrong". Is it a problem of Chrome or my regex?
I'd suggest:
var str = "http://something.org/dom/My_happy_dog_%28is%29cool!";
str.substring(str.lastIndexOf('/')+1).replace(/(_)|(%\d{2,})/g,' ');
JS Fiddle demo.
The reason I took this approach is that RegEx is fairly expensive, and is often tricky to fine tune to the point where edge-cases become less troublesome; so I opted to use simple string manipulation to reduce the RegEx work.
Effectively the above creates a substring of the given str variable, from the index point of the lastIndexOf('/') (which does exactly what you'd expect) and adding 1 to that so the substring is from the point after the / not before it.
The regex: (_) matches the underscores, the | just serves as an or operator and the (%\d{2,}) serves to match digit characters that occur twice in succession and follow a % sign.
The parentheses surrounding each part of the regex around the |, serve to identify matching groups, which are used to identify what parts should be replaced by the ' ' (single-space) string in the second of the arguments passed to replace().
References:
lastIndexOf().
replace().
substring().
You can use unescape to decode the percentages:
str = unescape("http://something.org/dom/My_happy_dog_%28is%29cool!")
str = str.replace("http://something.org/dom/","");
Maybe you could use a regular expression to pull out what you need, rather than getting rid of what you don't want. What is it you are trying to keep?
You can also chain them together as in:
str.replace("http://something.org/dom/", "").replace("something else", "");
You haven't defined the problem very exactly. To get rid of all stretches of characters ending in %<digit><digit> you'd say
var re = /.*%\d\d/g;
var str = str.replace(re, "");
ok, if you want to replace all that stuff I think that you would need something like this:
/(http:\/\/.*\.[a-z]{3}\/.*\/)|(\%[a-z0-9][a-z0-9])|_/g
test
var string = "http://something.org/dom/My_happy_dog_%28is%29cool!";
string = string.replace(/(http:\/\/.*\.[a-z]{3}\/.*\/)|(\%[a-z0-9][a-z0-9])|_/g,"");

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