Regex not getting entire substring

Question

My input string looks like this:

&hello=HI1&op=1h23&hello=&op=&hello=HI3&op=&hello=HI4&op=OP4

If hello has text, I'd like the data to be captured. The op parameter is optional and may or may not have a value. In the string above, I would like the following output (each line will be stored as a separate value in an array):

hello=HI&op=1h23
hello=HI3&op=
hello=HI4&op=OP4

I've got it mostly working but the problem is if op has a value with any letters in the word 'hello', the remaining part of op won't be captured. As you can see in the sample string above, the first op value is 1h23, after the h, the values 23 isn't captured.

https://regex101.com/r/Er0kEo/2

I've tried:

/&hello=[A-z 0-9]+&op=[^&hello]*/gi

This mostly works, except if op has a value that contains any of the letters in the word 'hello'. I've also tried:

/&hello=[A-z 0-9]+&op=.+?(?=&hello)/gi

Only captures first input. Also tried (?!&hello) - slightly better but doesn't capture the last input. Tried with \b and didn't get very far, neither did ^&hello$.

I feel like I'm missing something small but 5 hours in, I'm beat.

Does it mean all the keys are identical to `hello`? Is `&op` present in all the values? and you need to only extract those that have some text before `&op`? — Wiktor Stribiżew, Mar 06 '17 at 09:39
See https://jsfiddle.net/jqu5motj/1/, does it work as intended? — Wiktor Stribiżew, Mar 06 '17 at 09:45
@WiktorStribiżew: yes, that's perfect! It's so simple as well, a bit stunned I couldn't figure that out/didn't try just [^&]*. Thank you! — greentea, Mar 06 '17 at 14:55

Aziz Shaikh · Answer 1 · 2017-03-07T05:47:44.270

0

Using the regex /&(hello=\w*&op=\w*)/, will give the following required matches:

hello=HI&op=1h23
hello=HI3&op=
hello=HI4&op=OP4

JavaScript Demo

var pattern = /&(hello=\w*&op=\w*)/g;

var str = "&hello=HI1&op=1h23&hello=&op=&hello=HI3&op=&hello=HI4&op=OP4";

var result;

while (result = pattern.exec(str)) {
  console.log(result[1]);
}

edited Mar 07 '17 at 05:47

answered Mar 06 '17 at 09:31

Aziz Shaikh

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m87 · Accepted Answer · 2017-03-06T10:21:45.070

0

Try with the following regex ( using positive look-ahead ) :

hello=[a-z0-9]+&op=[^&]*

DEMO

JavaScript

var str = "&hello=HI1&op=1h23&hello=&op=&hello=HI3&op=&hello=HI4&op=OP4";
var result = str.match(/hello=[a-z0-9]+&op=[^&]*/gi);
console.log(result);

edited Mar 06 '17 at 10:21

answered Mar 06 '17 at 09:32

m87

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[`[A-z]` matches more than letters](http://stackoverflow.com/a/29771926/3832970), but it is not so relevant here, I guess. What is relevant, is that OP expects to have the results without leading `&`. Also, `.*?(?=&|$)` is an "overkill" if you compare it with `[^&]*`. – Wiktor Stribiżew Mar 06 '17 at 10:12
When I do, I will for sure. – Wiktor Stribiżew Mar 06 '17 at 10:26

score 0 · Answer 3 · answered Mar 06 '17 at 09:49

0

/hello=[a-z\s0-9]+&op=[a-z0-9]*/gi

Result

Match 1
Full match  1-18    `hello=HI1&op=1h23`
Match 2
Full match  30-43   `hello=HI3&op=`
Match 3
Full match  44-60   `hello=HI4&op=OP4`

https://regex101.com/r/Er0kEo/3

answered Mar 06 '17 at 09:49

lkdhruw

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Regex not getting entire substring

3 Answers3