Question

So I could write:

val res = """(\d*).*""".r.replaceAllIn(s,"""\1""")

So far I get literal “1” instead of the captured group.

Thank you in advance.

Answer 1

Try this : $1 instead of \1.

Scala’s Regex uses java.util.regex underneath (at least on the JVM). Now, if you look up replaceAll on Java docs, you’ll see this:

Note that backslashes () and dollar signs ($) in the replacement
string may cause the results to be different than if it were being
treated as a literal replacement string. Dollar signs may be treated
as references to captured subsequences as described above, and
backslashes are used to escape literal characters in the replacement
string.