Three ways of scala string interpolation

    String interpolation ： A mechanism for embedding variable references directly into the procedure string literal . Only in Scala-2.10 And later versions support .

1、's' String interpolator

written words 's' Allows you to use variables directly when processing strings . Anything in the scope String Variables can be used in strings .

usage 1：

stay println In the sentence String Variable ($name) Append to normal string (Hello) in ：

val name = "TRX"

println(s"Hello, $name") //output: Hello, TRX

usage 2：

The string inserter can also handle arbitrary expressions . Use 's' The string inserter handles any expression with (${1 + 1}) String (1 + 1) The following code snippet for . Any expression can be embedded in ${} in .

println(s "1 + 1 = ${1 + 1}") //output: 1 + 1 = 2

 

2、'f' String interpolator

written words 'f' The interpolator allows you to create a formatted string , Be similar to C In language printf. In the use of 'f' Interpolator , All variable references should be printf Style format specifier , Such as ％d,％i,％f etc. .

Let's take a general string as an example to append floating-point values (height = 1.9d) And string variables (name =“TRX”). The following code snippet implements 'f' Interpolator . here $name％s Print String Variable TRX and $height％2.2f Print floating point values 1.90.
 

val height = 1.9d
val name = "TRX"
println(f"$name%s is $height%2.2f meters tall") //TRX is 1.90 meters tall

3、'raw' String interpolator

'raw' The interpolator is similar to 's' Interpolator , But it does not perform literal escape within the string .

• 's' Interpolator for , The program code is as follows ：

println(s"Result = \n a \n b")

//  Output results  -

Result =
a
b

• 'raw' Interpolator for , The program code is as follows -

println(raw"Result = \n a \n b")


//  Output results  -

Result = \n a \n b