How to create multiline strings in Scala

This is an excerpt from 1st edition of the Scala Cookbook (partially modified for the internet). This is Recipe 1.2, “How to Create Multiline Strings in Scala.”

Problem

You want to create multiline strings within your Scala source code, like you can with the “heredoc” syntax of other languages.

Solution

In Scala you create multiline strings by surrounding your text with three double quotes:

val foo = """This is 
    a multiline
    String"""

Discussion

Although this solution works, the second and third lines in this example will end up with whitespace at the beginning of their lines. If you print the string, it looks like this:

This is 
    a multiline
    String

You can solve this problem in several different ways. First, you can left-justify every line after the first line of your string:

val foo = """This is 
a multiline
String"""

A cleaner approach is to add the stripMargin method to the end of your multiline string, and begin all lines after the first line with the pipe symbol (|):

val speech = """Four score and
               |seven years ago""".stripMargin

If you don’t like using the | symbol, you can use any character you like with the stripMargin method:

val speech = """Four score and
               #seven years ago""".stripMargin('#')

All of these approaches yield the same result, a multiline string with each line of the string left-justified:

Four score and
seven years ago

This results in a true multiline string, with a hidden \n character after the word “and” in the first line. To convert this multiline string into one continuous line you can add a replaceAll method after the stripMargin call, replacing all newline characters with blank spaces:

val speech = """Four score and
               |seven years ago
               |our fathers""".stripMargin.replaceAll("\n", " ")

This yields:

Four score and seven years ago our fathers

Another nice feature of Scala’s multiline string syntax is that you can include single- and double-quotes without having to escape them:

val s = """This is known as a 
    |"multiline" string 
    |or 'heredoc' syntax.""". stripMargin.replaceAll("\n", " ")

This results in this string:

This is known as a "multiline" string or 'heredoc' syntax.

Related

After the publication of the Cookbook, I wrote this article, A Scala way to convert a multiline String into a List.

this post is sponsored by my books:
#1 New Release	FP Best Seller	Learn Scala 3	Learn FP Fast