Interpolated Strings

There are three kinds of interpolated strings.

1. A String of the form s"foo ${bar}" will have the value of expression bar, converted to a String and inserted in place of ${bar}. If the expression bar returns an instance of a type other than String, a toString method will be invoked, if one exists. It is an error if it can’t be converted to a String.
2. The second kind provides printf formatting and uses the prefix f.
3. The third kind is called “raw” interpolated strings. It doesn’t expand escape characters, like \n.

code example

// The first way:
val name: String = "BrownWong"
println(s"My name is ${name}")
println(s"My name is $name") // 省略大括号

// The second way:
val money = 100F
println(f"I have ${money}%.2f $$") // "$$"输出"$"
println(f"I have $money%.2f $$")
println("I have %.2f $".format(money)) // 用字符串的format函数同样可以实现

// The third way:
println(raw"haha\nhaha")

output:

My name is BrownWong
My name is BrownWong
I have 100.00 $
I have 100.00 $
I have 100.00 $
haha\nhaha

Ref

《Programming Scala》