I have the following set of strings:
some_param[name]
some_param_0[name]
I wish to capture some_param, 0, name from them. My regex knowledge is pretty weak. I tried the following, but it doesn't work for both cases.
/^(\D+)_?(\d{0,2})\[?(.*?)\]?$/.exec("some_param_0[name]") //works except for the trailing underscore on "some_param"
What would be the correct regex?
/^(\w+?)_?(\d{0,2})(?:\[([^\[\]]*)\])?$/
(\w+?) uses a non-greedy quantifier to capture the identifier part without any trailing _.
_? is greedy so will beat the +? in the previous part.
(\d{0,2}) will capture 0-2 digits. It is greedy, so even if there is no _ between the identifier and digits, this will capture digits.
(?:...)? makes the square bracketed section optional.
\[([^\[\]]*)\] captures the contents of a square bracketed section that does not itself contain square brackets.
'some_param_0[name]'.match(/^(\w+?)_(\d{0,2})(?:\[([^\[\]]*)\])?$/)
produces an array like:
["some_param_0[name]", // The matched content in group 0.
"some_param", // The portion before the digits in group 1.
"0", // The digits in group 2.
"name"] // The contents of the [...] in group 3.
Note that the non-greedy quantifier might interact strangely with the bounded repetition in \d{0,2}.
'x1234[y]'.match(/^(\w+?)_?(\d{0,2})(?:\[([^\[\]]*)\])?$/)
yields
["x1234[y]","x12","34","y"]
/^([a-zA-Z_]+)(?:_(\d{0,2}))?(?:\[([^\[\]]*)\])?$/ but it looks like it doesn't work (at least, in Python)
_ is not captured in group 1.Got it! (taking from Mike's answer):
/^(\D+)(?:_(\d+))?(?:\[([^\]]*)\])/
'some_param[name]' => ('some_param', None, 'name')
'some_param_0[name]' => ('some_param', '0', 'name')
(at least, in Python it works)
UPDATE: A little extra I wrote fiddling with it, by making the result cleaner by using named groups:
^(?P<param>\D+)(?:_(?P<id>\d+))?(?:\[(?P<key>[^\]]*)\])
UPDATE:
/^([A-Za-z_]+)(?:_(\d+))?(?:\[([^\]]*)\])?$/, that seems to work in a lot of cases.Please ,check the follwing regexp "(\w+)_(\d)[(\w+)]" yo can test it @ http://rubular.com/
