What is the best way to capture everything except when faced with two or more new lines?
ex:
name1
address1
zipcode
name2
address2
zipcode
name3
address3
zipcode
One regex I considered was /[^\n\n]*\s*/g. But this stops when it is faced with a single \n character.
Another way I considered was /((?:.*(?=\n\n)))\s*/g. But this seems to only capture the last line ignoring the previous lines.
What is the best way to handle similar situation?
UPDATE
You can consider replacing the variable length separator with some known fixed length string not appearing in your processed text and then split. For instance:
> var s = "Hi\n\n\nBye\nCiao";
> var x = s.replace(/\n{2,}/, "#");
> x.split("#");
["Hi", "Bye
Ciao"]
I think it is an elegant solution. You could also use the following somewhat contrived regex
> s.match(/((?!\n{2,})[\s\S])+/g);
["Hi", "
Bye
Ciao"]
and then process the resulting array by applying the trim() string method to its members in order to get rid of any \n at the beginning/end of every string in the array.
((.+)\n?)*(you probably want to make the groups non-capturing, left it as is for readability)
The inner part (.+)\n? means "non-empty line" (at least one non-newline character as . does not match newlines unless the appropriate flag is set, followed by an optional newline)
Then, that is repeated an arbitrary number of times (matching an entire block of non-blank lines).
However, depending on what you are doing, regexp probably is not the answer you are looking for. Are you sure just splitting the string by \n\n won't do what you want?
Do you have to use regex? The solution is simple without it.
var data = 'name1...';
var matches = data.split('\n\n');
To access an individual sub section split it by \n again.
//the first section's name
var name = matches[0].split('\n')[0];
Related
I need to replace everything between : and , with a | multiple times.
I have a server list like server1:127.0.0.1,server2:127.0.0.2,server3:127.0.0.3.
Basically, I need to remove all the IPs and replace them with some |.
So far I was able to do this:
resultList = serverList.replace(/:.*,/g, '|')
The problem is that the result list is server1|server3:127.0.0.3.
How can I replace every occurrence?
/:.*,/ is greedily matching :127.0.0.1,server2:127.0.0.2. Remember that quantifiers like * will match as much as they can while still allowing the rest of the pattern to match.
Consider specifying [^,] instead of .. This will exclude commas from matching and therefore limit the match to just the region you want to remove.
resultList = serverList.replace(/:[^,]*,/g, '|')
You could take a lazy approach with ? (Matches as few characters as possible).
var string = 'server1:127.0.0.1,server2:127.0.0.2,server3:127.0.0.3';
console.log(string.replace(/:.*?(,|$)/g, '|'));
How can I use regex in javascript to match the phone number and only the phone number in the sample string below? The way I have it written below matches "PHONE=9878906756", I need it to only match "9878906756". I think this should be relatively simple, but I've tried putting negating like characters around "PHONE=" with no luck. I can get the phone number in its own group, but that doesn't help when assigning to the javascript var, which only cares what matches.
REGEX:
/PHONE=([^,]*)/g
DATA:
3={STATE=, SSN=, STREET2=, STREET1=, PHONE=9878906756,
MIDDLENAME=, FIRSTNAME=Dexter, POSTALCODE=, DATEOFBIRTH=19650802,
GENDER=0, CITY=, LASTNAME=Morgan
The way you're doing it is right, you just have to get the value of the capture group rather than the value of the whole match:
var result = str.match(/PHONE=([^,]*)/); // Or result = /PHONE=([^,]*)/.exec(str);
if (result) {
console.log(result[1]); // "9878906756"
}
In the array you get back from match, the first entry is the whole match, and then there are additional entries for each capture group.
You also don't need the g flag.
Just use dataAfterRegex.substring(6) to take out the first 6 characters (i.e.: the PHONE= part).
Try
var str = "3={STATE=, SSN=, STREET2=, STREET1=, PHONE=9878906756, MIDDLENAME=, FIRSTNAME=Dexter, POSTALCODE=, DATEOFBIRTH=19650802, GENDER=0, CITY=, LASTNAME=Morgan";
var ph = str.match(/PHONE\=\d+/)[0].slice(-10);
console.log(ph);
I've got some string that contain invisible characters, but they are in somewhat predictable places. Typically the surround the piece of text I want to extract, and then after the 2nd occurrence I want to keep the rest of the text.
I can't seem to figure out how to both key off of the invisible characters, and exclude them from my result. To match invisibles I've been using this regex: /\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F/ which does seem to work.
Here's an example: [invisibles]Keep as match 1[invisibles]Keep as match 2
Here's what I've been using so far without success:
/([\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F]+)(.+)([\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F]+)/(.+)
I've got the capture groups in there, but it's bee a while since I've had to use regex's in this way, so I know I'm missing something important. I was hoping to just make the invisible matches non-capturing groups, but it seems that JavaScript does not support this.
Something like this seems like what you want. The second regex you have pretty much works, but the / is in totally the wrong place. Perhaps you weren't properly reading out the group data.
var s = "\x0EKeep as match 1\x0EKeep as match 2";
var r = /[\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F]+(.+)[\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F]+(.+)/;
var match = s.match(r);
var part1 = match[1];
var part2 = match[2];
I am trying to extract the first character after the last underscore in a string with an unknown number of '_' in the string but in my case there will always be one, because I added it in another step of the process.
What I tried is this. I also tried the regex by itself to extract from the name, but my result was empty.
var s = "XXXX-XXXX_XX_DigitalF.pdf"
var string = match(/[^_]*$/)[1]
string.charAt(0)
So the final desired result is 'D'. If the RegEx can only get me what is behind the last '_' that is fine because I know I can use the charAt like currently shown. However, if the regex can do the whole thing, even better.
If you know there will always be at least one underscore you can do this:
var s = "XXXX-XXXX_XX_DigitalF.pdf"
var firstCharAfterUnderscore = s.charAt(s.lastIndexOf("_") + 1);
// OR, with regex
var firstCharAfterUnderscore = s.match(/_([^_])[^_]*$/)[1]
With the regex, you can extract just the one letter by using parentheses to capture that part of the match. But I think the .lastIndexOf() version is easier to read.
Either way if there's a possibility of no underscores in the input you'd need to add some additional logic.
Friends,
I'm new to both Javascript and Regular Expressions and hope you can help!
Within a Javascript function I need to check to see if a comma(,) appears 1 or more times. If it does then there should be one or more numbers either side of it.
e.g.
1,000.00 is ok
1,000,00 is ok
,000.00 is not ok
1,,000.00 is not ok
If these conditions are met I want the comma to be removed so 1,000.00 becomes 1000.00
What I have tried so is:
var x = '1,000.00';
var regex = new RegExp("[0-9]+,[0-9]+", "g");
var y = x.replace(regex,"");
alert(y);
When run the alert shows ".00" Which is not what I was expecting or want!
Thanks in advance for any help provided.
strong text
Edit
strong text
Thanks all for the input so far and the 3 answers given. Unfortunately I don't think I explained my question well enough.
What I am trying to achieve is:
If there is a comma in the text and there are one or more numbers either side of it then remove the comma but leave the rest of the string as is.
If there is a comma in the text and there is not at least one number either side of it then do nothing.
So using my examples from above:
1,000.00 becomes 1000.00
1,000,00 becomes 100000
,000.00 is left as ,000.00
1,,000.00 is left as 1,,000.00
Apologies for the confusion!
Your regex isn't going to be very flexible with higher orders than 1000 and it has a problem with inputs which don't have the comma. More problematically you're also matching and replacing the part of the data you're interested in!
Better to have a regex which matches the forms which are a problem and remove them.
The following matches (in order) commas at the beginning of the input, at the end of the input, preceded by a number of non digits, or followed by a number of non digits.
var y = x.replace(/^,|,$|[^0-9]+,|,[^0-9]+/g,'');
As an aside, all of this is much easier if you happen to be able to do lookbehind but almost every JS implementation doesn't.
Edit based on question update:
Ok, I won't attempt to understand why your rules are as they are, but the regex gets simpler to solve it:
var y = x.replace(/(\d),(\d)/g, '$1$2');
I would use something like the following:
^[0-9]{1,3}(,[0-9]{3})*(\.[0-9]+)$
[0-9]{1,3}: 1 to 3 digits
(,[0-9]{3})*: [Optional] More digit triplets seperated by a comma
(\.[0-9]+): [Optional] Dot + more digits
If this regex matches, you know that your number is valid. Just replace all commas with the empty string afterwards.
It seems to me you have three error conditions
",1000"
"1000,"
"1,,000"
If any one of these is true then you should reject the field, If they are all false then you can strip the commas in the normal way and move on. This can be a simple alternation:
^,|,,|,$
I would just remove anything except digits and the decimal separator ([^0-9.]) and send the output through parseFloat():
var y = parseFloat(x.replace(/[^0-9.]+/g, ""));
// invalid cases:
// - standalone comma at the beginning of the string
// - comma next to another comma
// - standalone comma at the end of the string
var i,
inputs = ['1,000.00', '1,000,00', ',000.00', '1,,000.00'],
invalid_cases = /(^,)|(,,)|(,$)/;
for (i = 0; i < inputs.length; i++) {
if (inputs[i].match(invalid_cases) === null) {
// wipe out everything but decimal and dot
inputs[i] = inputs[i].replace(/[^\d.]+/g, '');
}
}
console.log(inputs); // ["1000.00", "100000", ",000.00", "1,,000.00"]