String Interpolation refers to substitution of defined variables or expressions in a given String with respected values. String Interpolation provides an easy way to process String literals. To apply this feature of Scala, we must follow few rules:
- String must be defined with starting character as s / f /raw.
- Variables in the String must have '$' as prefix.
- Expressions must be enclosed within curly braces ({, }) and '$' is added as prefix.
Syntax:// x and y are defined
val str = s"Sum of $x and $y is ${x+y}"
- s Interpolator: Within the String, we can access variables, object fields, functions calls, etc.
Example 1: variables and expressions:
Output:
str1: Sum of $x and $y is ${x+y}
str2: Sum of 20 and 10 is 30
Example 2: function call
Output:
str1: Sum of $x and $y is ${add(x, y)}
str2: Sum of 20 and 10 is 30
- f Interpolator: This interpolation helps in formatting numbers easily.
To understand how format specifiers work refer Format Specifiers.
Example 1: printing upto 2 decimal place:
Output:
str1: Value of x is $x%.2f
str2: Value of x is 20.60
Example 2: setting width in integers:
Output:
Value of x is $x%04d
Value of x is 0011
If we try to pass a Double value while formatting is done using %d specifier, compiler outputs an error. In case of %f specifier, passing Int is acceptable.
- raw Interpolator: String Literal should start with ‘raw’. This interpolator treats escape sequences same as any other character in a String.
Example :printing escape sequence:
Output:
str1: Hello
World
str2: Hello\nWorld
