Develop Reference

How can I add a dot between two numbers?

I'm trying to add a dot between two numbers. It's about article numbers, for now they were like XXXXX or XXXXXX and now should be XXX.XX or XXX.XXX which I can't figure out.
Article numbers are loaded automatically from database since there are a lot of them. Right now, they are 99-87503 or 99-400031, and from now on should be 99.875.03 or 99.400.031.
I've tried with specifying numbers, filters and patterns none of which worked.
Current AngularJs code:
<div class="status">
99.{{Manipulated()}} |
<p ng-model="Manipulated"
class="rwd-info-msg {{Manipulated.cssClass}}">
{{Manipulated.text}}
</p>
</div>
This 99. is just a prefix that should be at every article number.
I'm pretty new to AngularJS, so any help would be appreciated.

The naive thing you could do is
var num = 9876543;
var res = num.toString().replace(/^(\d{3})(.*)/ig, '$1.$2');
console.log(num, '->', res);
Here, the (\d{3}) part captures the first 3 digits while the (.*) captures the rest.
You can then access each part with $1 to get the first captured group and $2 to get the second captured group.
I'm certain that there are way better solutions, but that a starting point.

This expression,
(?<=^[0-9]{3})
with a replacement of . might also work.
const regex = /(?<=^[0-9]{3})/g;
const str = `9876544`;
const subst = `.`;
const result = str.replace(regex, subst);
console.log(result);
The expression is explained on the top right panel of regex101.com, if you wish to explore/simplify/modify it, and in this link, you can watch how it would match against some sample inputs, if you like.

AngularJS way of doing this is creating a custom filter:
app.filter('addDot', function() {
return function(number) {
return number.toString().slice(0,3) + number.toString().slice(3);
};
})
and use it in your template like:
<div class="article-status">
99.{{getManipulatedArticle(article).artnr | addDot}} </p>
</div>

Regular expression to match a string which is NOT matched by a given regexp

I've been hoving around by some answers here, and I can't find a solution to my problem:
I have this regexp which matches everyting inside an HTML span tag, including contents:
<span\b[^>]*>(.*?)</span>
and I want to find a way to make a search in all the text, except for what is matched with that regexp.
For example, if my text is:
var text = "...for there is a class of <span class="highlight">guinea</span> pigs which..."
... then the regexp would match:
<span class="highlight">guinea</span>
and I want to be able to make a regexp such that if I search for "class", regexp will match "...for there is a class of..."
and will not match inside the tag, like in
"... class="highlight"..."
The word to be matched ("class") might be anywhere within the text. I've tried
(?!<span\b[^>]*>(.*?)</span>)class
but it keeps searching inside tags as well.
I want to find a solution using only regexp, not dealing with DOM nor JQuery. Thanks in advance :).

Although I wouldn't recommend this, I would do something like below
(class)(?:(?=.*<span\b[^>]*>))|(?:(?<=<\/span>).*)(class)
You can see this in action here
Rubular Link for this regex
You can capture your matches from the groups and work with them as needed. If you can, use a HTML parser and then find matches from the text element.

It's not pretty, but if I get you right, this should do what you wan't. It's done with a single RegEx but js can't (to my knowledge) extract the result without joining the results in a loop.
The RegEx: /(?:<span\b[^>]*>.*?<\/span>)|(.)/g
Example js code:
var str = '...for there is a class of <span class="highlight">guinea</span> pigs which...',
pattern = /(?:<span\b[^>]*>.*?<\/span>)|(.)/g,
match,
res = '';
match = pattern.exec(str)
while( match != null )
{
res += match[1];
match = pattern.exec(str)
}
document.writeln('Result:' + res);
In English: Do a non capturing test against your tag-expression or capture any character. Do this globally to get the entire string. The result is a capture group for each character in your string, except the tag. As pointed out, this is ugly - can result in a serious number of capture groups - but gets the job done.
If you need to send it in and retrieve the result in one call, I'd have to agree with previous contributors - It can't be done!

Javascript Regular expression to remove unwanted <br>,

I have a JS stirng like this
<div id="grouplogo_nav"><br> <ul><br> <li><a class="group_hlfppt" target="_blank" href="http://www.hlfppt.org/">&nbsp;</a></li><br> </ul><br> </div>
I need to remove all <br> and $nbsp; that are only between > and <. I tried to write a regular expression, but didn't got it right. Does anybody have a solution.
EDIT :
Please note i want to remove only the tags b/w > and <

Avoid using regex on html!
Try creating a temporary div from the string, and using the DOM to remove any br tags from it. This is much more robust than parsing html with regex, which can be harmful to your health:
var tempDiv = document.createElement('div');
tempDiv.innerHTML = mystringwithBRin;
var nodes = tempDiv.childNodes;
for(var nodeId=nodes.length-1; nodeId >= 0; --nodeId) {
if(nodes[nodeId].tagName === 'br') {
tempDiv.removeChild(nodes[nodeId]);
}
}
var newStr = tempDiv.innerHTML;
Note that we iterate in reverse over the child nodes so that the node IDs remain valid after removing a given child node.
http://jsfiddle.net/fxfrt/

myString = myString.replace(/^( |<br>)+/, '');
... where /.../ denotes a regular expression, ^ denotes start of string, ($nbsp;|<br>) denotes " or <br>", and + denotes "one or more occurrence of the previous expression". And then simply replace that full match with an empty string.

s.replace(/(>)(?: |<br>)+(\s?<)/g,'$1$2');
Don't use this in production. See the answer from Phil H.
Edit: I try to explain it a bit and hope my english is good enough.
Basically we have two different kinds of parentheses here. The first pair and third pair () are normal parentheses. They are used to remember the characters that are matched by the enclosed pattern and group the characters together. For the second pair, we don't need to remember the characters for later use, so we disable the "remember" functionality by using the form (?:) and only group the characters to make the + work as expected. The + quantifier means "one or more occurrences", so or <br> must be there one or more times. The last part (\s?<) matches a whitespace character (\s), which can be missing or occur one time (?), followed by the characters <. $1 and $2 are kind of variables that are replaces by the remembered characters of the first and third parentheses.
MDN provides a nice table, which explains all the special characters.

You need to replace globally. Also don't forget that you can have the being closed . Try this:
myString = myString.replace(/( |<br>|<br \/>)/g, '');

This worked for me, please note for the multi lines
myString = myString.replace(/( |<br>|<br \/>)/gm, '');

myString = myString.replace(/^( |<br>)+/, '');
hope this helps

RegExp: how to exclude matched groups from $N?

I've made a working regexp, but i think it's not the best use-case:
el = '<div style="color:red">123</div>';
el.replace(/(<div.*>)(\d+)(<\/div>)/g, '$1<b>$2</b>$3');
// expecting result: <div style="color:red"><b>123</b></div>
After googling i've found that (?: ... ) in regexps - means ignoring group match, thus:
el.replace(/(?:<div.*>)(\d+)(?:<\/div>)/g, '<b>$1</b>');
// returns <b>123</b>
but i need an expecting result from 1st example.
Is there a way to exclude 'em? just to write replace(/.../, '<b>$1</b>')?
This is just a little case for understanding how to exclude groups in regexp. And i know, what we can't parse HTML with regexp :)

So you want to get the same result while only using the replacement <b>$1</b>?
In your case just replace(/\d+/, '<b>$&</b>') would suffice.
But if you want to make sure there are div tags around the number, you could use lookarounds and \K like in the following expression. Except that JS does not support lookbehind nor \K, so you're out of luck, you have to use a capturing group for that in JS.
<div[^>]*>\K\d+(?=</div>)

There nothing wrong with a replacement value of '$1<b>$2</b>$3'. I would just change your regex to this:
el = '<div style="color:red">123</div>';
el.replace(/(<div[^>]*>)(\d+)(<\/div>)/g, '$1<b>$2</b>$3');
Changing how it matches the first div keeps the full match on the div tags, but makes sure it matches the minimum possible before the closing > of the first div tag rather than the maximum possible.
With your regex, you would not get what you wanted with this input string:
el = '<div style="color:red">123</div><div style="color:red">456</div>';
The problem with using something like:
el.replace(/\d+/, '<b>$&</b>')
is that doesn't work properly with things like this:
el = '<div style="margin-left: 10px">123</div>'
because it picks up the numbers inside the div tag.

REGEX to match starting and ending span tags without their inner text

I am using the following RegEx to do a replacement in a string:
<\/?(span)\b(?:\s+class="highlight")?>
But this regex has a flaw... Take this sample code for example:
<p>
Some text here
<span class="highlight">This is highlighted</span>
<span>This is not highlighted</span>
</p>
My regex will match both of the span tags although i only want the one with the class="highlight" set. How can I achieve this using RegEx?
PS: please do not tell me that I should not use RegEx for this because i will downgrade your answer as it is off-topic. This is a question for the RegEx guys.
EDIT: based on the accepted answer below i am using the following regex to do a replace
NOTE: code is in javascript (mootools)
var regex = new RegExp("(<span[^>]+class\\s*=\\s*(\"|')highlight\\2[^>]*>)(.*?)(</span>)",'g');
var replaced = element.get('html').replace(regex, "$3");
element.set('html', replaced);
The above regex will replace a some text here with "some text here" (without the double quotes)

This should give the most flexibility.
(<span[^>]+class\s*=\s*("|')highlight\2[^>]*>)[^<]*(</span>)
UPDATE:
The captured groups you need for the opening and closing tags are \1 and \3.

Just to show you that an alternative solution is not only possible bot also better than using regex:
$$('span.highlight').each(function (node, idx, Elem) {
var txt = document.createTextNode(Elem.get('text'));
node.parentNode.replaceChild(txt, node)
});
See this fiddle: http://jsfiddle.net/Tomalak/umgZp/
(And this is just off the top of my hat, I've had zero exposure to MooTools so far. There might be more elegant ways than this.)

You are obviously stating that that class=highlight part is optional, by placing a ? in front of the group capturing it.
This should do it for you:
var regex = /(?:<span\s+[^>]*?\s*class\s*=\s*('|")(?:\S+\s+)?highlight(?:\s+\S+)?\1[^>]*>|<\/span>/;
This will also include SPAN tags with class attributes like a b c highlight e f g.
Also, if you want to capture a SPAN tag with its matching ending, you can use this, and access groups 1 and 3 respectively for the opening and ending tags:
var regex = /(<span\s+[^>]*?\s*class\s*=\s*('|")(?:\S+\s+)?highlight(?:\s+\S+)?\1[^>]*>).*?(<\/span>)/;