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javaregexreplaceall

How to double escape double quote?

Say I have this String in java:

This a "text". This is inches 30". And another 20\"

I want to find all inches (double quotes after a number) and add a second escape for it, if it doesn't have yet.

So after the change, the string would be like this, printed in console:

This is a "text". This is inches 30\". And another 20\"

So the regex must check if there is a number before the double quote and if there is not a escape character already...

thanks!!

Solution

  • Try with Positive Lookbehind

    String str="This a \"text\". This is inches 30\". And another 20\\\"";
System.out.println(str.replaceAll("(?<=\\d)\"", "\\\\\""));

    output:

    This a "text". This is inches 30\". And another 20\"

    Here is Online demo as well.

    Pattern explanation:

      (?<=                     look behind to see if there is:
    \d                       digits (0-9)
  )                        end of look-behind
  \"                       '"'