I'm using this regex:
([\w\s]+)(=|!=)([\w\s]+)( (or|and) ([\w\s]+)(=|!=)([\w\s]+))*
to match a string such as this: i= 2 or i =3 and k!=4
When I try to extract values using m.group(index), I get:
(i, =, 2, **and k!=4**, and, k, ,!=, 4).
Expected output: (i, =, 2, or, i, =, 3, and, k , !=, 4) How do i extract the values correctly?
P.S. m.matches() returns true.
you are trying to match with a regexp on an expression...you might want to use a parser, because this regexp (when you have it) can't be extended further..but a parser can be extended at any time
for example, consider using antlr (ANTLR: Is there a simple example?)
This is because your third set of parens (the one that you use for repeating expressions) is what's confusing you. Try using a non-capturing parens:
([\w\s]+)(=|!=)([\w\s]+)(?: (or|and) ([\w\s]+)(=|!=)([\w\s]+))*
Why not simplify your expression to match exactly what you're looking for?
!?=|(?:or|and)|\b(?:(?!or|and)[\w\s])+\b
Live Demo hover over the blue bubbles in the text area to see exactly what is matched
Sample Text
i= 2 or i =1234 and k!=4
Matches Found
[0][0] = i
[1][0] = =
[2][0] = 2
[3][0] = or
[4][0] = i
[5][0] = =
[6][0] = 1234
[7][0] = and
[8][0] = k
[9][0] = !=
[10][0] = 4
Everything in brackets makes a capturing group which you can later access via index. But you can make the group which you do not need non-capturing: (?: ... ), then it will not be considered at Matcher.group(int).
