I have this sample text, which is retrieved from the class name on an html element:
rich-message err-test1 erroractive
rich-message err-test2 erroractive
rich-message erroractive err-test1
err-test2 rich-message erroractive
I am trying to match the "test1"/"test2" data in each of these examples. I am currently using the following regex, which matches the "err-test1" type of word. I can't figure out how to limit it to just the data after the hyphen(-).
/err-(\S*)/ig
Head hurts from banging against this wall.
From what I am reading, your code already works.
Regex.exec() returns an array of results on success.
The first element in the array (index 0) returns the entire string, after which all () enclosed elements are pushed into this array.
var string = 'rich-message err-test1 erroractive';
var regex = new RegExp('err-(\S*)', 'ig');
var result = regex.exec(string);
alert(result[0]) --> returns err-test1
alert(result[1]) --> returns test1
You could try 'err-([^ \n\r]*)' - but are you sure that it is the regex that is the problem? Are you using the whole result, not just the first capture?
The stuff after the - should be in the results array. The first item is all the matching text (e.g. "err-test1") and the next items are the matches from the capture parentheses (e.g. "test1").
myregex = /err-(\S*)/ig;
mymatch = myregex.exec("data with matches in it");
testnum = mymatch[1];
Here's a reference site.
Related
I have a dynamically generated text like this
xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0
How can I remove everything before Map ...? I know there is a hard coded way to do this by using substring() but as I said these strings are dynamic and before Map .. can change so I need to do this dynamically by removing everything before 4th index of - character.
You could remove all four minuses and the characters between from start of the string.
var string = 'xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0',
stripped = string.replace(/^([^-]*-){4}/, '');
console.log(stripped);
I would just find the index of Map and use it to slice the string:
let str = "xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0"
let ind = str.indexOf("Map")
console.log(str.slice(ind))
If you prefer a regex (or you may have occurrences of Map in the prefix) you man match exactly what you want with:
let str = "xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0"
let arr = str.match(/^(?:.+?-){4}(.*)/)
console.log(arr[1])
I would just split on the word Map and take the first index
var splitUp = 'xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0'.split('Map')
var firstPart = splitUp[0]
Uses String.replace with regex expression should be the popular solution.
Based on the OP states: so I need to do this dynamically by removing everything before 4th index of - character.,
I think another solution is split('-') first, then join the strings after 4th -.
let test = 'xxxxxx-xxxx-xxxxx-xxxxx-Map-B-844-0'
console.log(test.split('-').slice(4).join('-'))
I Would like to extract the Twitter handler names from a text string, using a regex. I believe I am almost there, except for the ">" that I am including in my output. How can I change my regex to be better, and drop the ">" from my output?
Here is an example of a text string value:
"PlaymakersZA, Absa, DiepslootMTB"
The desired output would be an array consisting of the following:
PlaymakersZA, Absa, DiepslootMTB
Here is an example of my regex:
var array = str.match(/>[a-z-_]+/ig)
Thank you!
You can use match groups in your regex to indicate the part you wish to extract.
I set up this JSFiddle to demonstrate.
Basically, you surround the part of the regex that you want to extract in parenthesis: />([a-z-_]+)/ig, save it as an object, and execute .exec() as long as there are still values. Using index 1 from the resulting array, you can find the first match group's result. Index 0 is the whole regex, and next indices would be subsequent match groups, if available.
var str = "PlaymakersZA, Absa, DiepslootMTB";
var regex = />([a-z-_]+)/ig
var array = regex.exec(str);
while (array != null) {
alert(array[1]);
array = regex.exec(str);
}
You could just strip all the HTML
var str = "PlaymakersZA, Absa, DiepslootMTB";
$handlers = str.replace(/<[^>]*>|\s/g,'').split(",");
I'm pretty frustrated with regex right now. Given:
var text = "This is a sentence.\nThis is another sentence\n\nThis is the last sentence!"
I want regex to return to me:
{"This is a sentence.\n", "This is another sentence\n\n", "This is the last sentence!"}
I think i should use
var matches = text.match(/.+[\n+\Z]/)
but \Z doesn't seem to work. Does javascript have an end of string matcher?
You can use the following regex.
var matches = text.match(/.+\n*/g);
Working Demo
Or you could match a newline sequence "one or more" times or the end of the string.
var matches = text.match(/.+(?:\n+|$)/g);
Try this one: /(.+\n*)/g
See it here: http://regex101.com/r/wK8oX3/1
If you wanted an array and didn't want to keep the "\n" around you could do...
var strings = text.split("\n");
which would yield
["This is a sentence.", "This is another sentence", "", "This is the last sentence!"]
if you wanted to get rid of that empty string chain a filter onto the split...
var strings = text.split("\n").filter(function(s){ return s !== ""; });
Maybe not what you want tho, also not as efficient as the regex options already proposed.
Edit: as torazaburo pointed out using Boolean as the filter function is cleaner than a callback.
var strings = text.split("\n").filter(Boolean);
Edit Again: I keep getting one upped, using the /\n+/ expression is even cooler.
var strings = text.split(/\n+/);
To get an array of sentences:
var matches = text.match(/.+?(?:(?:\\n)+|$)/g);
You can try this,
text.match(/.+/g)
I'm fairly sure after spending the night trying to find an answer that this isn't possible, and I've developed a work around - but, if someone knows of a better method, I would love to hear it...
I've gone through a lot of iterations on the code, and the following is just a line of thought really. At some point I was using the global flag, I believe, in order for match() to work, and I can't remember if it was necessary now or not.
var str = "#abc#def#ghi&jkl";
var regex = /^(?:#([a-z]+))?(?:&([a-z]+))?$/;
The idea here, in this simplified code, is the optional group 1, of which there is an unspecified amount, will match #abc, #def and #ghi. It will only capture the alpha characters of which there will be one or more. Group 2 is the same, except matches on & symbol. It should also be anchored to the start and end of the string.
I want to be able to back reference all matches of both groups, ie:
result = str.match(regex);
alert(result[1]); //abc,def,ghi
alert(result[1][0]); //abc
alert(result[1][1]); //def
alert(result[1][2]); //ghi
alert(result[2]); //jkl
My mate says this works fine for him in .net, unfortunately I simply can't get it to work - only the last matched of any group is returned in the back reference, as can be seen in the following:
(additionally, making either group optional makes a mess, as does setting global flag)
var str = "#abc#def#ghi&jkl";
var regex = /(?:#([a-z]+))(?:&([a-z]+))/;
var result = str.match(regex);
alert(result[1]); //ghi
alert(result[1][0]); //g
alert(result[2]); //jkl
The following is the solution I arrived at, capturing the whole portion in question, and creating the array myself:
var str = "#abc#def#ghi&jkl";
var regex = /^([#a-z]+)?(?:&([a-z]+))?$/;
var result = regex.exec(str);
alert(result[1]); //#abc#def#ghi
alert(result[2]); //jkl
var result1 = result[1].toString();
result[1] = result1.split('#')
alert(result[1][1]); //abc
alert(result[1][2]); //def
alert(result[1][3]); //ghi
alert(result[2]); //jkl
That's simply not how .match() works in JavaScript. The returned array is an array of simple strings. There's no "nesting" of capture groups; you just count the ( symbols from left to right.
The first string (at index [0]) is always the overall matched string. Then come the capture groups, one string (or null) per array element.
You can, as you've done, rearrange the result array to your heart's content. It's just an array.
edit — oh, and the reason your result[1][0] was "g" is that array indexing notation applied to a string gets you the individual characters of the string.
I need to do a lot of regex things in javascript but am having some issues with the syntax and I can't seem to find a definitive resource on this.. for some reason when I do:
var tesst = "afskfsd33j"
var test = tesst.match(/a(.*)j/);
alert (test)
it shows
"afskfsd33j, fskfsd33"
I'm not sure why its giving this output of original and the matched string, I am wondering how I can get it to just give the match (essentially extracting the part I want from the original string)
Thanks for any advice
match returns an array.
The default string representation of an array in JavaScript is the elements of the array separated by commas. In this case the desired result is in the second element of the array:
var tesst = "afskfsd33j"
var test = tesst.match(/a(.*)j/);
alert (test[1]);
Each group defined by parenthesis () is captured during processing and each captured group content is pushed into result array in same order as groups within pattern starts. See more on http://www.regular-expressions.info/brackets.html and http://www.regular-expressions.info/refcapture.html (choose right language to see supported features)
var source = "afskfsd33j"
var result = source.match(/a(.*)j/);
result: ["afskfsd33j", "fskfsd33"]
The reason why you received this exact result is following:
First value in array is the first found string which confirms the entire pattern. So it should definitely start with "a" followed by any number of any characters and ends with first "j" char after starting "a".
Second value in array is captured group defined by parenthesis. In your case group contain entire pattern match without content defined outside parenthesis, so exactly "fskfsd33".
If you want to get rid of second value in array you may define pattern like this:
/a(?:.*)j/
where "?:" means that group of chars which match the content in parenthesis will not be part of resulting array.
Other options might be in this simple case to write pattern without any group because it is not necessary to use group at all:
/a.*j/
If you want to just check whether source text matches the pattern and does not care about which text it found than you may try:
var result = /a.*j/.test(source);
The result should return then only true|false values. For more info see http://www.javascriptkit.com/javatutors/re3.shtml
I think your problem is that the match method is returning an array. The 0th item in the array is the original string, the 1st thru nth items correspond to the 1st through nth matched parenthesised items. Your "alert()" call is showing the entire array.
Just get rid of the parenthesis and that will give you an array with one element and:
Change this line
var test = tesst.match(/a(.*)j/);
To this
var test = tesst.match(/a.*j/);
If you add parenthesis the match() function will find two match for you one for whole expression and one for the expression inside the parenthesis
Also according to developer.mozilla.org docs :
If you only want the first match found, you might want to use
RegExp.exec() instead.
You can use the below code:
RegExp(/a.*j/).exec("afskfsd33j")
I've just had the same problem.
You only get the text twice in your result if you include a match group (in brackets) and the 'g' (global) modifier.
The first item always is the first result, normally OK when using match(reg) on a short string, however when using a construct like:
while ((result = reg.exec(string)) !== null){
console.log(result);
}
the results are a little different.
Try the following code:
var regEx = new RegExp('([0-9]+ (cat|fish))','g'), sampleString="1 cat and 2 fish";
var result = sample_string.match(regEx);
console.log(JSON.stringify(result));
// ["1 cat","2 fish"]
var reg = new RegExp('[0-9]+ (cat|fish)','g'), sampleString="1 cat and 2 fish";
while ((result = reg.exec(sampleString)) !== null) {
console.dir(JSON.stringify(result))
};
// '["1 cat","cat"]'
// '["2 fish","fish"]'
var reg = new RegExp('([0-9]+ (cat|fish))','g'), sampleString="1 cat and 2 fish";
while ((result = reg.exec(sampleString)) !== null){
console.dir(JSON.stringify(result))
};
// '["1 cat","1 cat","cat"]'
// '["2 fish","2 fish","fish"]'
(tested on recent V8 - Chrome, Node.js)
The best answer is currently a comment which I can't upvote, so credit to #Mic.