java regex : getting a substring from a string which can vary

Question

I have a String like - \"Bangalore,India=Karnataka\". From this String I would like to extract only the substring \"Bangalore\". In this case the regex

Answer 1

Try this one:

^(.+?)(?:,.*?)?=.*$

Explanation:

^               # Begining of the string
  (             # begining of capture group 1
    .+?         # one or more any char non-greedy
  )             # end of group 1
  (?:           # beginig of NON capture group
    ,           # a comma
    .*?         # 0 or more any char non-greedy
  )?            # end of non capture group, optional
  =             # equal sign
  .*            # 0 or more any char
$               # end of string

Updated: I thougth OP have to match Bangalore,India=Karnataka or Bangalore=Karnataka but as farr as I understand it is Bangalore,India=Karnataka or Bangalore so the regex is much more simpler :

^([^,]+)

This will match, at the begining of the string, one or more non-comma character and capture them in group 1.