regex - extract word between 2nd underscore and 3rd underscore or space

Question

i want to extract the word after the 2nd & 3rd underscore (_) or the word between the 2nd underscore & space.

my sample data would be:

COL_POS_CJMA_CA_03.09.17
COL_DPU_CJER_CK_03.08.17
COL_POS_CJNE CA_03.09.2017
COL_DPU_CJEK CK_03.08.2017

my results should be:

CJMA
CJER
CJNE
CJEK

I already have this _[^_]*_([^_]*)_ And I could extract the 1st two results. If any one could help me extract the 3rd & 4th results

A regex that says between the 3rd underscore or a space

Answer 1

You could go for

^(?:[^_]+_){2}([^_ ]+)

See a demo on regex101.com.

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Broken down, this says:

^         # beginning of string
(?:       # non-capturing group
    [^_]+ # not _, at least once
    _     # _
){2}      # repeat the group twice
([^_ ]+)  # capture characters not _ or spaces to group 1

... or, split by _ and analyze the result as an array, ie result[2].