Java String Regex replacement

Question

Sample Input:

a:b
a.in:b
asds.sdsd:b
a:b___a.sds:bc___ab:bd

Sample Output:

a:replaced
a.in:replaced
asds.sdsd:replaced
a:replaced___a.sds:replaced___ab:replaced

String which comes after : should be replaced with custom function. I have done the same without Regex. I feel it can be replaced with regex as we are trying to extract string out of specific pattern.

For first three cases, it's simple enough to extract String after :, but I couldn't find a way to deal with third case, unless I split the string ___ and apply the approach for first type of pattern and again concatenate them.

Answer 1

Just replace only the letters with exists next to : with the string replaced.

string.replaceAll("(?<=:)[A-Za-z]+", "replaced");

DEMO

or

If you also want to deal with digits, then add \d inside the char class.

string.replaceAll("(?<=:)[A-Za-z\\d]+", "replaced");

• RaceBase: just to update, :bc___ can be something like this :b566 or :4545. I guess we should consider numbers too
• Avinash Raj: then add \\d inside the char class.
• RaceBase: sorry for not clarifying. It can contain any data :[email protected] or :b@_g+.com .But guranteed not to contain : and ____ as these are self-defined pattern
• RaceBase: could be dump question now, how do I call custom function instead of directly replacing with "replaced". My custom function should get the matching string matcher.group()
• Avinash Raj: ask this as a new question. I think you need to include the replaceAll function within while function.

Answer 2

(:)[a-zA-Z]+

You can simply do this with string.replaceAll.Replace by 1ドルreplaced.See demo.

https://regex101.com/r/fX3oF6/18