How to insert double quotes into String with interpolation in scala

Question

Having trouble escaping all the quotes in my function

(basic usage of it -> if i find a string do nothing, if its not a string add " in the begin and end)

code snippet :

  def putTheDoubleQuotes(value: Any): Any = {
    value match {
      case s: String => s //do something ...
      case _  => s"\"$value\"" //not working
    }
  }

only thing that worked was :

case _ => s"""\"$value\""""

is there a better syntax for this ?

it looks terrible and the IDE (IntelliJ) marks it in red (but lets you run it which really pisses me!!!!!)

Answer 1

This is a bug in Scala:

escape does not work with string interpolation

but maybe you can use:

scala> import org.apache.commons.lang.StringEscapeUtils.escapeJava import org.apache.commons.lang.StringEscapeUtils.escapeJava  scala> escapeJava("this is a string\nover two lines") res1: java.lang.String = this is a string\nover two lines 

Answer 2

You don't need to escape quotes in triple-quoted string, so s""""$value""""" will work. Admittedly, it doesn't look good either.

Answer 3

Another solution (also mentioned in the Scala tracker) is to use

case _ => s"${'"'}$value${'"'}"

Still ugly, but sometimes perhaps may be preferred over triple quotes.

It seems an escape sequence $" was suggested as a part of SIP-24 for 2.12:

case _ => s"$"$value$""

This SIP was never accepted, as it contained other more controversial suggestions. Currently there is an effort to get escape sequence $" implemented in 2.13 as Pre SIP/mini SIP $” escapes in interpolations.

Answer 4

An example:

scala> val username="admin"
> username: String = admin

scala> val pass="xyz"
> pass: String = xyz

scala> println(s"""{"username":"$username", "pass":"$pass"}""")
> {"username":"admin", "pass":"xyz"}