lets say I have
String str = "sdahasdahellodsadsahdashellodsadsadsahehllo";
and I want to replace every letter that isn't part of hello with the character '_', how would I do it? the output would be something like:
_______hello_________hello_____________
What regex would I have to use? I've used [^hello] but it matches each individual character, not the word itself, so I have a bunch of random letters floating about.
You may replace:
(?:^|\G|(?<=hello))(?!hello).
With:
_
Breakdown:
(?: - Start of a non-capturing group.
^ - Match starts at the beginning of the string/line,| - OR...\G - starts immediately following the previous match,| - OR...(?<=hello) - is immediately preceded by "hello".) - Close the non-capturing group.(?!hello) - Not followed by "hello".. - Any single character (aside from linebreaks).Java demo:
String input = "sdahasdahellodsadsahdashellodsadsadsahehllo";
String output = input.replaceAll("(?:^|\\G|(?<=hello))(?!hello).", "_");
System.out.println(output); // ________hello__________hello_______________