After coming to the shocking realization that regular expressions in JavaScript are somewhat different from the ones in PCE, I am stuck with the following.
In php I extract a number after x:
(?x)[0-9]+
In JavaScript the same regex doesn't work, due to invalid group resulting from the capturing parenthesis difference.
So I am trying to achieve the same trivial functionality, but I keep getting both the x and the number:
(?:x)([0-9]+)
How do I capture the number after x without including x?
This works too:
/(?:x)([0-9]+)/.test('YOUR_STRING');
Then, the value you want is:
RegExp.$1 // group 1
You can try the following regex: (?!x)[0-9]+
fiddle here: https://jsfiddle.net/xy6x938e/1/
This is assuming that you are now looking for an x followed by a number, it uses a capture group to capture just the numbers section.
var myString = "x12345";
var myRegexp = /x([0-9]+)/g;
var match = myRegexp.exec(myString);
var myString2 = "z12345";
var match2 = myRegexp.exec(myString2);
if(match != null && match.length > 1){
alert('match1:' + match[1]);
}
else{
alert('no match 1');
}
if(match2 != null && match2.length > 1){
alert('match2:' + match2[1]);
}
else{
alert('no match 2');
}
(\d+) try this!
i have tested on this tool with x12345
http://www.regular-expressions.info/javascriptexample.html
How do I capture the number after x without including x?
In fact, you just want to extract a sequence of digits after a fixed string/known pattern.
Your PCRE (PHP) regex, (?x)[0-9]+, is wrong becaue (?x) is an inline version of a PCRE_EXTENDED VERBOSE/COMMENTS flag (see "Pattern Modifiers"). It does not do anything meaningful in this case, (?x)[0-9]+ is equal to [0-9]+ or \d+.
You can use
console.log("x15 x25".match(/(?<=x)\d+/g));
You can also use a capturing group and then extract Group 1 value after a match is obtained:
const match = /x(\d+)/.exec("x15");
if (match) {
console.log(match[1]); // Getting the first match
}
// All matches
const matches = Array.from("x15,x25".matchAll(/x(\d+)/g), x=>x[1]);
console.log(matches);
You still can use exclusive pattern (?!...)
So, for your example it will be /(?!x)[0-9]+/. Give a try to the following:
/(?!x)\d+/.exec('x123')
// => ["123"]
Related
I want a Javascript regex or with any possible solution,
For a given string finds all the substrings that start with a particular string and end with a particular character. The returned set of subStrings can be an Array.
this string can also have nested within parenthesis.
var str = "myfunc(1,2) and myfunc(3,4) or (myfunc(5,6) and func(7,8))";
starting char = "myfunc" ending char = ")" . here ending character should be first matching closing paranthesis.
output: function with arguments.
[myfunc(1,2),
myfunc(3,4),
myfunc(5,6),
func(7,8)]
I have tried with this. but, its returning null always.
var str = "myfunc(1,2) and myfunc(3,4) or (myfunc(5,6) and func(7,8))";
var re = /\myfunc.*?\)/ig
var match;
while ((match = re.exec(str)) != null){
console.log(match);
}
Can you help here?
I tested your regex and it seems to work fine:
let input = "myfunc(1,2) and myfunc(3,4) or (myfunc(5,6) and func(7,8))"
let pattern = /myfunc.*?\)/ig
// there is no need to use \m since it does nothing, and NO you dont need it even if you use 'm' at the beginning.
console.log(input.match(pattern))
//[ "myfunc(1,2)", "myfunc(3,4)", "myfunc(5,6)" ]
If you use (?:my|)func\(.+?\) you will be able to catch 'func(7,8)' too.
(?:my|)
( start of group
?: non capturing group
my| matches either 'my' or null, this will match either myfunc or func
) end of group
Test the regex here: https://regex101.com/r/3ujbdA/1
I'm working with a string where I need to extract the first n characters up to where numbers begin. What would be the best way to do this as sometimes the string starts with a number: 7EUSA8889er898 I would need to extract 7EUSA But other string examples would be SWFX74849948, I would need to extract SWFX from that string.
Not sure how to do this with regex my limited knowledge is blocking me at this point:
^(\w{4}) that just gets me the first four characters but I don't really have a stopping point as sometimes the string could be somelongstring292894830982 which would require me to get somelongstring
Using \w will match a word character which includes characters and digits and an underscore.
You could match an optional digit [0-9]? from the start of the string ^and then match 1+ times A-Za-z
^[0-9]?[A-Za-z]+
Regex demo
const regex = /^[0-9]?[A-Za-z]+/;
[
"7EUSA8889er898",
"somelongstring292894830982",
"SWFX74849948"
].forEach(s => console.log(s.match(regex)[0]));
Can use this regex code:
(^\d+?[a-zA-Z]+)|(^\d+|[a-zA-Z]+)
I try with exmaple and good worked:
1- somelongstring292894830982 -> somelongstring
2- 7sdfsdf5456 -> 7sdfsdf
3- 875werwer54556 -> 875werwer
If you want to create function where the RegExp is parametrized by n parameter, this would be
function getStr(str,n) {
var pattern = "\\d?\\w{0,"+n+"}";
var reg = new RegExp(pattern);
var result = reg.exec(str);
if(result[0]) return result[0].substr(0,n);
}
There are answers to this but here is another way to do it.
var string1 = '7EUSA8889er898';
var string2 = 'SWFX74849948';
var Extract = function (args) {
var C = args.split(''); // Split string in array
var NI = []; // Store indexes of all numbers
// Loop through list -> if char is a number add its index
C.map(function (I) { return /^\d+$/.test(I) === true ? NI.push(C.indexOf(I)) : ''; });
// Get the items between the first and second occurence of a number
return C.slice(NI[0] === 0 ? NI[0] + 1 : 0, NI[1]).join('');
};
console.log(Extract(string1));
console.log(Extract(string2));
Output
EUSA
SWFX7
Since it's hard to tell what you are trying to match, I'd go with a general regex
^\d?\D+(?=\d)
After coming to the shocking realization that regular expressions in JavaScript are somewhat different from the ones in PCE, I am stuck with the following.
In php I extract a number after x:
(?x)[0-9]+
In JavaScript the same regex doesn't work, due to invalid group resulting from the capturing parenthesis difference.
So I am trying to achieve the same trivial functionality, but I keep getting both the x and the number:
(?:x)([0-9]+)
How do I capture the number after x without including x?
This works too:
/(?:x)([0-9]+)/.test('YOUR_STRING');
Then, the value you want is:
RegExp.$1 // group 1
You can try the following regex: (?!x)[0-9]+
fiddle here: https://jsfiddle.net/xy6x938e/1/
This is assuming that you are now looking for an x followed by a number, it uses a capture group to capture just the numbers section.
var myString = "x12345";
var myRegexp = /x([0-9]+)/g;
var match = myRegexp.exec(myString);
var myString2 = "z12345";
var match2 = myRegexp.exec(myString2);
if(match != null && match.length > 1){
alert('match1:' + match[1]);
}
else{
alert('no match 1');
}
if(match2 != null && match2.length > 1){
alert('match2:' + match2[1]);
}
else{
alert('no match 2');
}
(\d+) try this!
i have tested on this tool with x12345
http://www.regular-expressions.info/javascriptexample.html
How do I capture the number after x without including x?
In fact, you just want to extract a sequence of digits after a fixed string/known pattern.
Your PCRE (PHP) regex, (?x)[0-9]+, is wrong becaue (?x) is an inline version of a PCRE_EXTENDED VERBOSE/COMMENTS flag (see "Pattern Modifiers"). It does not do anything meaningful in this case, (?x)[0-9]+ is equal to [0-9]+ or \d+.
You can use
console.log("x15 x25".match(/(?<=x)\d+/g));
You can also use a capturing group and then extract Group 1 value after a match is obtained:
const match = /x(\d+)/.exec("x15");
if (match) {
console.log(match[1]); // Getting the first match
}
// All matches
const matches = Array.from("x15,x25".matchAll(/x(\d+)/g), x=>x[1]);
console.log(matches);
You still can use exclusive pattern (?!...)
So, for your example it will be /(?!x)[0-9]+/. Give a try to the following:
/(?!x)\d+/.exec('x123')
// => ["123"]
Hi I need to get a string inside 2 pair of square brackets in javascript using regular expressions.
here is my string [[12]],23,asd
So far what I tried is using this pattern '\[\[[\d]+\]\]'
and I need to get the value 12 using regular expressions
You can use the following regex,
\[\[(\d+)\]\]
This will extract 12 from [[12]],23,asd
It uses capture groups concept
You can capture the digits using groups
"[12]],23,asd".match(/\[\[(\d+)\]\]/)[1]
=> "12"
\[\[(\d+)\]\]
Try this.Grab the capture or group 1.See demo.
var re = /\[\[(\d+)\]\]/gs;
var str = '[[12]],23,asd';
var m;
while ((m = re.exec(str)) != null) {
if (m.index === re.lastIndex) {
re.lastIndex++;
}
// View your result using the m-variable.
// eg m[0] etc.
}
Here is a regex you can use, capture groups to get $1 and $2 which will be 12 and 43 respectively
\[\[(\d+)\]\]\S+\[\[(\d+)\]\]
If you need to get 12 you can just use what you mentioned with a capturing group \[\[(\d+)\]\]
var myRegexp= /\[\[(\d+)\]\]/;
var myString='[[12]],23,asd';
var match = myRegexp.exec(myString);
console.log(match[1]); // will have 12
I've only done it with 2 regExps, haven't found the way to do it with one:
var matches = '[[12]],23,asd'.match(/\[{2}(\d+)\]{2}/ig),
intStr = matches[0].match(/\d+/ig);
console.log(intStr);
I have a string with this format:
#someID#tn#company#somethingNew#classing#somethingElse#With
There might be unlimited #-separated words, but definitely the whole string begins with #
I have written the following regexp, though it matches it, but I cannot get each #-separated word, and what I get is the last recursion and the first (as well as the whole string). How can I get an array of every word in an element separately?
(?:^\#\w*)(?:(\#\w*)+) //I know I have ruled out second capturing group with ?: , though doesn't make much difference.
And here is my Javascript code:
var reg = /(?:^\#\w*)(?:(\#\w*)+)/g;
var x = null;
while(x = reg.exec("#someID#tn#company#somethingNew#classing#somethingElse#With"))
{
console.log(x);
}
And here is the result (Firebug, console):
["#someID#tn#company#somet...sing#somethingElse#With", "#With"]
0
"#someID#tn#company#somet...sing#somethingElse#With"
1
"#With"
index
0
input
"#someID#tn#company#somet...sing#somethingElse#With"
EDIT :
I want an output like this with regular expression if possible:
["#someID", "#tn", #company", "#somethingNew", "#classing", "#somethingElse", "#With"]
NOTE that I want a RegExp solution. I know about String.split() and String operations.
You can use:
var s = '#someID#tn#company#somethingNew#classing#somethingElse#With'
if (s.substr(0, 1) == "#")
tok = s.substr(1).split('#');
//=> ["someID", "tn", "company", "somethingNew", "classing", "somethingElse", "With"]
You could try this regex also,
((?:#|#)\w+)
DEMO
Explanation:
() Capturing groups. Anything inside this capturing group would be captured.
(?:) It just matches the strings but won't capture anything.
#|# Literal # or # symbol.
\w+ Followed by one or more word characters.
OR
> "#someID#tn#company#somethingNew#classing#somethingElse#With".split(/\b(?=#|#)/g);
[ '#someID',
'#tn',
'#company',
'#somethingNew',
'#classing',
'#somethingElse',
'#With' ]
It will be easier without regExp:
var str = "#someID#tn#company#somethingNew#classing#somethingElse#With";
var strSplit = str.split("#");
for(var i = 1; i < strSplit.length; i++) {
strSplit[i] = "#" + strSplit[i];
}
console.log(strSplit);
// ["#someID", "#tn", "#company", "#somethingNew", "#classing", "#somethingElse", "#With"]