Javascript Regex Invalid Group

Question

Re-writing the question since named capturing groups are not the main issue.

/([a-zA-Z ]*)([0-9]*)/g

The code is working now fine but var m = /([a-zA-Z ]*)([0-9]*)/g.exec('Ashok : 9830011245') is only giving me the Ashok as the result.

m[0]: "Ashok"
m[1]: "Ashok"
m[2]: ""

Sample Strings I need to work it on:

var strings = [
"Ashok : 9812340245",
"Amit Singh :\nChakmir 9013123427\n\nHitendra Singh:\n\nM. : 9612348943",
"ANIL  AGARWAL :  \n09331234728\n09812340442\nMAYANK AGARWAL : \n09123416042",
"JAGDISH SINGH :      098123452187 \n09830111234",
"MD QYAMUDDIN : 09433186333,\n09477215123\nMD TAJUDDIN : \n09831429111\nGYASUDDIN ANSARI :\n08961383686 \nMD BABUDDIN : \n09433336456 \n09903568555\nJAWE",
"Viay Singh : 9330938789,\nBijay Singh : 9330938222",
"Nilu :          09830161000,\n09331863222,\n09830071333,\nSantosh Upadhayay :       09831379555,\n09331727858,\n09830593322"
];

Please guide.

*`does not support named capturing groups`* yet :p https://github.com/tc39/proposal-regexp-named-groups — Jaromanda X, Sep 20 '17 at 08:32
@WiktorStribiżew I have removed the name but now my exec function is not returning the numeric group value at all. After Removing my named groups, the new regex is: /([a-zA-Z ]*)([0-9]*)/g. — Siddharth Srivastva, Sep 20 '17 at 08:41
Try [`([a-zA-Z]+)\s*([0-9]+)`](https://regex101.com/r/uJ60VC/1). Note you most probably have line breaks in the original string, not 2-char `\n`s. Note it is a very bad idea to use a regex that matches an empty string with a `g` modifier (like `/([a-zA-Z ]*)([0-9]*)/g`) - it might just cause an infinite loop. — Wiktor Stribiżew, Sep 20 '17 at 08:43
@WiktorStribiżew Thanks but Nopes. It does not help. I have added the sample string which I need to match from. Please check the question or the regex101.com link. — Siddharth Srivastva, Sep 20 '17 at 08:51
Please at least provide the expected result for `var s = "ANIL AGARWAL : \n09339874728\n09865410442\nMAYANK AGARWAL : \n09836516042 Ashok : 9830012344\nJAGDISH SINGH : \n09830234587\n09832356187"` string. I guess you have newlines in your string, not 2-char `\n`s. — Wiktor Stribiżew, Sep 20 '17 at 08:52
@WiktorStribiżew Also, no strings are empty so no infinite loop. — Siddharth Srivastva, Sep 20 '17 at 08:52
I said the pattern may match an empty string, and that is not good. — Wiktor Stribiżew, Sep 20 '17 at 08:53
@WiktorStribiżew Will edit it for not matching an empty string. — Siddharth Srivastva, Sep 20 '17 at 08:54
@WiktorStribiżew Please visit this link: https://regex101.com/r/jMWZmj/2 for test results — Siddharth Srivastva, Sep 20 '17 at 08:55
I will only help you if you provide a real life test case via http://jsfiddle.net. I am sure your string does not look like what you think it does. — Wiktor Stribiżew, Sep 20 '17 at 08:57
@WiktorStribiżew Thanks your Solution worked for my three test string. Will post the jsfiddle.net link for sample strings. — Siddharth Srivastva, Sep 20 '17 at 09:00
@WiktorStribiżew Please see this jsfiddle.net link for more samples: https://jsfiddle.net/vishsid73/s2p30513/ — Siddharth Srivastva, Sep 20 '17 at 09:14
@WiktorStribiżew your solution broke for couple of them. Please have a look and please guide. — Siddharth Srivastva, Sep 20 '17 at 09:15
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/154868/discussion-between-siddharth-srivastva-and-wiktor-stribizew). — Siddharth Srivastva, Sep 20 '17 at 09:17

score 1 · Accepted Answer · answered Sep 20 '17 at 10:13

It seems you may extract all the substrings you need with

/^([^:0-9\n]+)\s*(?::\s*)?([0-9]*)/gm

See the regex demo.

Details

^ - start of the line (as m enables the multiline mode)
([^:0-9\n]+) - 1 or more chars other than :, digits and newline
\s* - 1 or more whitespaces
(?::\s*)? - an optional sequence of : and 0+ whitespaces
([0-9]*) - zero or more digits.

JS demo:

var strings = [
"Ashok : 9812340245",
"Amit Singh :\nChakmir 9013123427\n\nHitendra Singh:\n\nM. : 9612348943",
"ANIL  AGARWAL :  \n09331234728\n09812340442\nMAYANK AGARWAL : \n09123416042",
"JAGDISH SINGH :      098123452187 \n09830111234",
"MD QYAMUDDIN : 09433186333,\n09477215123\nMD TAJUDDIN : \n09831429111\nGYASUDDIN ANSARI :\n08961383686 \nMD BABUDDIN : \n09433336456 \n09903568555\nJAWE",
"Viay Singh : 9330938789,\nBijay Singh : 9330938222",
"Nilu :          09830161000,\n09331863222,\n09830071333,\nSantosh Upadhayay :       09831379555,\n09331727858,\n09830593322"
];

var regex = /^([^:0-9\n]+)\s*(?::\s*)?([0-9]*)/gm;
for (var s of strings) {
  console.log("Looking in: ", s, "\n--------------------------");
 console.log(s.match(regex));
}
// To output groups:
console.log("====Outputting groups====");
for (var s of strings) {
 while(m=regex.exec(s))
    console.log(m[1].trim(), ";", m[2]);
}

Javascript Regex Invalid Group

1 Answers1