We Keep Coding

Regex - Match a string between second occurance of characters

I have a string of text that looks something like this:
?q=search&something=that&this=example/
In that example, I need to grab that . I'm using the following regex below:
var re = new RegExp("\&(.*?)\&");
Which going re[1] is giving me:
something=that - but it needs to be only that
I tried:
var re = new RegExp("\=(.*?)\&");
But that gives me everything from the first equals sign, so:
search&something=that
Is the output when it just needs to be:
that
I need to somehow target the second occurrences of 2 characters and grab whats in between them. How best do I go about this?

You can use
/something=([^&]+)/
and take the first group, see the JavaScript example:
let url = '?q=search&something=that&this=example/';
let regex = /something=([^&]+)/
let match = regex.exec(url);
console.log(match[1]);

split seems more suited to your case:
"?q=search&something=that&this=example/".split("&")[1].split("=")[1]
Then you could also implement a simple method to extract any wanted value :
function getValue(query, index) {
const obj = query.split("&")[index];
if(obj) obj.split("=")[1]
}
getValue("?q=search&something=that&this=example/", 1);

regex test How to return only exact match

I have this code:
var search_term = postAdminID
// Wildcards Search
var search = new RegExp(search_term, "i");
sdsFilter = $.grep(sdsInfo.products, function(element, index) {
var sted = search.exec(element.AdminID)
return sted;
postAdminID is the index of a spesific post in an array.
element.AdminID is the corresponding index I am seraching for.
PROBLEM:
Whenever I try to execute this search I get every matching index also parts of indexes matched.
Lets say I want to retrieve index #78. The above code returns: 78, 178, 278, 10078 and so forth. I only want the exact index - not every index containing the index.
I have tried .exec and test
I have looked in every post here on stackoverflow that I can find.
Please help.
How can I specify for regex that it should only look for the entire "string" ?

The issue is the search pattern you are using.
In REGEX you can match the beginning and the end of the line (of the string in the case of a single-line string). For this, add ^ at the beginning of the search pattern, and $ at the end.
For example ^78$ will only match the index 78, not 178,278...
If you're looking in a string with delimiters that contains many indexes, you will have to add the delimited in the search pattern, or split the string and search its elementary element.

Try this regex :
\b78\b
\b will make sure this is only 78, and not a number containing 78.
In your case, search_term should be :
var search_term = "\b"+postAdminID+"\b"

Thank you for your input. Both suggestions did make things work. Except that they restricted use of the script for other purposes. I wanted to use one search algorithm for more than just integer keys.
In the end I ended up with this script, using: return element.AdminID == postAdminID;
var search_term = postAdminID
// Wildcards Search
var search = new RegExp(search_term, "i");
sdsFilter = $.grep(sdsInfo.products, function(element, index) {
var sted = search.exec(element.AdminID)
return element.AdminID == postAdminID;
});
I also added several search.exec to the mix in order for my script to become more versatile and flexible. But thank you again for your valuble input.

Whats wrong with this regex logic

I am trying to fetch the value after equal sign, its works but i am getting duplicated values , any idea whats wrong here?
// Regex for finding a word after "=" sign
var myregexpNew = /=(\S*)/g;
// Regex for finding a word before "=" sign
var mytype = /(\S*)=/g;
//Setting data from Grid Column
var strNew = "QCById=20";
var matchNew = myregexpNew.exec(strNew);
var newtype = mytype.exec(strNew);
alert(matchNew);
https://jsfiddle.net/6vjjv0hv/

exec returns an array, the first element is the global match, the following ones are the submatches, that's why you get ["=20", "20"] (using console.log here instead of alert would make it clearer what you get).
When looking for submatches and using exec, you're usually interested in the elements starting at index 1.
Regarding the whole parsing, it's obvious there are better solution, like using only one regex with two submatches, but it depends on the real goal.

You can try without using Regex like this:
var val = 'QCById=20';
var myString = val.substr(val.indexOf("=") + 1);
alert(myString);
Presently exec is returning you the matched value.

REGEXP.exec(SOMETHING) returns an array (see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/exec).
The first item in the array is the full match and the rest matches the parenthesized substrings.

You do not get duplicated values, you just get an array of a matched value and the captured text #1.
See RegExp#exec() help:
If the match succeeds, the exec() method returns an array and updates properties of the regular expression object. The returned array has the matched text as the first item, and then one item for each capturing parenthesis that matched containing the text that was captured.
Just use the [1] index to get the captured text only.
var myregexpNew = /=(\S*)/g;
var strNew = "QCById=20";
var matchNew = myregexpNew.exec(strNew);
if (matchNew) {
console.log(matchNew[1]);
}
To get values on both sides of =, you can use /(\S*)=(\S*)/g regex:
var myregexpNew = /(\S*)=(\S*)/g;
var strNew = "QCById=20";
var matchNew = myregexpNew.exec(strNew);
if (matchNew) {
console.log(matchNew[1]);
console.log(matchNew[2]);
}
Also, you may want to add a check to see if the captured values are not undefined/empty since \S* may capture an empty string. OR use /(\S+)=(\S+)/g regex that requires at least one non-whitespace character to appear before and after the = sign.

Get string from other string with match()

I try to get the 00-8.
Why this code do not returns me the 00-8 ?
<script>
var pageDetailsSecond = "a='00-8'b='13-'a+='00-2'b+='3333'c='4'";
var phone1 = pageDetailsSecond.match("a='(.*)'");
var phone1 = phone1[0];
var card_Phone = phone1;
alert(card_Phone);
</script>
Actually I get a='00-8'.

Because what you try to match includes a=....
But when you find it, you can strip it from the match found.
Checked with jsfiddle: http://jsfiddle.net/pbo5x9dx/
var pageDetailsSecond = "a='00-8'b='13-'a+='00-2'b+='3333'c='4'";
alert(pageDetailsSecond)
var phones = pageDetailsSecond.match("a='(.*?)'");
var phone1 = phones[1];
alert(phone1)
** edit: ** fix for non-greedy match, checked with http://jsfiddle.net/pbo5x9dx/1/

Because the array returned by match() will contain the entire match in the first array slot, and the capture groups in subsequent elements.
The array contents will be:
[
[0] = "a='00-8'",
[1] = '00-8'
]
What you want is phone1[1] instead of phone1[0], which contains just the portion of the match specified by your capture group (.*).
Based on the updated question, the regex pattern should be changed to:
"a='(.*?)'"
By default, regex patterns try to match as much as possible (known as "greedy"). The pattern is saying "match any number of any characters between ' characters. This now includes 00-8'b='13-'a+='00-2'b+='3333'c='4. By adding the ?, this changes the behaviour to "lazy". In other words, match as little as possible, and your regex is back to matching only 00-8 as before.

javascript, regex parse string content in curly brackets

i am new to regex. I am trying to parse all contents inside curly brackets in a string. I looked up this post as a reference and did exactly as one of the answers suggest, however the result is unexpected.
Here is what i did
var abc = "test/abcd{string1}test{string2}test" //any string
var regex = /{(.+?)}/
regex.exec(abc) // i got ["{string1}", "string1"]
//where i am expecting ["string1", "string2"]
i think i am missing something, what am i doing wrong?
update
i was able to get it with /g for a global search
var regex = /{(.*?)}/g
abc.match(regex) //gives ["{string1}", "{string2}"]
how can i get the string w/o brackets?

"test/abcd{string1}test{string2}test".match(/[^{}]+(?=\})/g)
produces
["string1", "string2"]
It assumes that every } has a corresponding { before it and {...} sections do not nest. It will also not capture the content of empty {} sections.

var abc = "test/abcd{string1}test{string2}test" //any string
var regex = /{(.+?)}/g
var matches;
while(matches = regex.exec(abc))
console.log(matches);

Try this:
var abc = "test/abcd{string1}test{string2}test" //any string
var regex = /{(.+?)}/g //g flag so the regex is global
abc.match(regex) //find every match
a good place to read about Regex in javascript is here, and a nice place to test is here
good luck!

Nothing wrong. But you'll need to look at your capturing groups (the second element in the array) to get the content you wanted (you can ignore the first). To get all occurences, it's not enough to run exec once, you'll need to loop over the results using match.
Edit: nevermind that, afaik you can't access capturing groups with match. A simpler solution would be using a positive lookahead, as Mike Samuel suggested.

This result:
["{string1}", "string1"]
is showing you that for the first match, the entire regex matched "{string1}" and the first capturing parentheses matched "string1".
If you want to get all matches and see all capturing parens of each match, you can use the "g" flag and loop through, calling exec() multiple times like this:
var abc = "test/abcd{string1}test{string2}test"; //any string
var regex = /{(.+?)}/g;
var match, results = [];
while (match = regex.exec(abc)) {
results.push(match[1]); // save first captured parens sub-match into results array
}
// results == ["string1", "string2"]
You can see it work here: http://jsfiddle.net/jfriend00/sapfm/

try this for file
const fs = require('fs');
fs.readFile('logs.txt', function(err, data) {
if(err) throw err;
const paragraph = "'" + data + "'";
const regex = /\d+\<;>\S+\<;>(\d+)\<;/g;
const found = paragraph.match(regex);
console.log(found);
})