I have a data array like below i need to format it like shown

a = ["8619 [EC006]", "9876 [ED009]", "1034 [AX009]"]

Need to format like ["EC006", "ED009", "AX009"]

can any one please help

CodePudding user response：

Input

a = ["8619 [EC006]", "9876 [ED009]", "1034 [AX009]"]

Code

p a.collect { |x| x[/\[(.*)\]/, 1] }

Output

["EC006", "ED009", "AX009"]

CodePudding user response：

arr = ["8619 [EC006]", "9876 [ED009]", "1034 [AX009]"]

To merely extract the strings of interest, assuming the data is formatted correctly, we may write the following.

arr.map { |s| s[/(?<=\[)[^\]]*/] }
  #=> ["EC006", "ED009", "AX009"]

See String#[] and Demo

In the regular expression (?<=\[) is a positive lookbehind that asserts the previous character is '['. The ^ at the beginning of the character class [^\]] means that any character other than ']' must be matched. Appending the asterisk ([^\]]*) causes the character class to be matched zero or more times.

To confirm the correctness of the formatting as well, use

arr.map { |s| s[/\A[1-9]\d{3} \[\K[A-Z]{2}\d{3}(?=]\z)/] }
  #=> ["EC006", "ED009", "AX009"]

Demo

Note that at the link I replaced \A and \z with ^ and $, respectively, in order to test the regex against multiple strings.

This regular expression can be broken down as follows.

\A        # match beginning of string
[1-9]     # match a digit other than zero
\d{3}     # match 3 digits
[ ]       # match one space
\[        # match '['
\K        # reset start of match to current stringlocation and discard
          # all characters previously matched from match that is returned
[A-Z]{2}  # match 2 uppercase letters
\d{3}     # match 3 digits
(?=]\z)   # positive lookahead asserts following character is
          # ']' and that character is at the end of the string

In the above I placed a space character in a character class ([ ]) merely to make it visible to the reader.