Question

I have a string like this:

this is my text
more text
more text

text I want
is below

I just want the text below the double line break and not the stuff before.

Here is what I thought should work:

myString.replaceFirst(".+?(\n\n)","");

However it does not work. Any help would be greatly appreciated

Answer 1

You should use the below regex for your purpose: –

str = str.replaceFirst("(?s).+?(\n\n)", "");

Because, you want to match anything including the newline character before it encounters two newline characters back to back.

---

Note that dot(.) does not matches a newline, so it would stop matching on encountering the first newline character.

If you want your dot(.) to match newline, you can use Pattern.DOTALL, which in case of str.replaceFirst, is achieved by using (?s) expression.

From the documentation of Pattern.DOTALL: –

In dotall mode, the expression . matches any character, including a
line terminator. By default this expression does not match line
terminators.

Dotall mode can also be enabled via the embedded flag expression (?s).