Scala Data Types and Variables

Scala has all data types available to Java as well as its own, in Scala there are different variables and types. In this article we will look in detail at Scala data types and variables.

Below are few data types in Scala:

SN	Data Type	Description
1	Byte	8 bit signed value. Range from -128 to 127
2	Short	16 bit signed value. Range -32768 to 32767
3	Int	32 bit signed value. Range -2147483648 to 2147483647
4	Long	64 bit signed value. -9223372036854775808 to 9223372036854775807
5	Float	32 bit IEEE 754 single-precision float
6	Double	64 bit IEEE 754 double-precision float
7	Char	16 bit unsigned Unicode character. Range from U+0000 to U+FFFF
8	String	A sequence of Chars
9	Boolean	Either the literal true or the literal false
10	Unit	This means void or nothing.
11	Null	Null or empty
12	Nothing	Nothing data type of Scala
13	Any	This is higher level, means can take any data type.
14	AnyRef	Super type of Any

Escape Sequence In Scala

Below are escape sequences in Scala:

SN	Escape Seq	Unicode/Code	Details
1	\b	\u0008	backspace BS
2	\t	\u0009	horizontal tab HT
3	\n	\u000c	formfeed FF
4	\f	\u000c	formfeed FF
5	\r	\u000d	carriage return CR
6	\”	\u0022	double quote “
7	\’	\u0027	single quote .
8	\\	\u005c	backslash \

Variables In Scala

In any programming language we use variables to hold certain values, some numeric, float or string values, same variables exist in Scala as well, they hold certain data types and values in memory. Based on data types variable may have different size and memory requirement for example an Int will take less memory than a Float.

Variable Declaration

We can specify variable name and type and then a value to variable that is how variable is declared. Also there is other form where we don’t need so specify type and still can declare variable, let’s see the syntax of both:

Variable with type syntax:

val <Variable type> = <Variable value>

Variable without type syntax:

val <Variable type> = <Variable value>

Variable Type Inference

Scala compiler does not need developer to specify variable types while declaration and when value is assigned to it at that time it determines type of variable. We already saw a above declaration.

Example:

val age = 20
val name = “Jonny”

Val vs Var in Scala

Val is a keyword used to declare variable as immutable/final, in case of object it makes them singleton in nature and such variables can’t be reassigned.Var is a keyword used to declare normal variables which are mutable and can be reassigned with new values.

Examples of Variables:

 
object VariableExmaple {
 
  def main(args: Array[String]): Unit = {
 
	//Mutable variables
	var age = 10
	var amount = 20.24f
	age = age +20
	var name = "Jonny"
	name = name + " and Rong"
	var message = "Hello " + name
 
	//Immutable variables
	val immutableAge = 10 //We cant change values of these
	val immutableName = "Jonny English" //We cant change values of these
 
	println("Mutable variables age: "+age+" Name: "+name + " Message: "+message)
	println("Immutable variables age: "+immutableAge+" Name: "+immutableName)
  }
 
}

Output:

Mutable variables age: 30 Name: Jonny and Rong Message: Hello Jonny and Rong

Immutable variables age: 10 Name: Jonny English

What is Tuple variable in Scala

Tuple are special variables which can be created easily by declaring multiple variables in one, it allows to have a maximum 22 variables in one tuple.

Example of Tuples:

val myDetail = (10, "Jonny")
val myAddress = ("ZZZ Street", "XYZ City", "ABC Country")

In the above example both variables are tuples, myDetail variable has two different types of variable first Int and second String.

myAddress variable has three variables of String type. We don’t need to declare type as Scala automatically infers type based on assigned values.

How to Use Tuples

We can use tuples by name of tuple then dot (.) and then _<number of variable which we want to access>.

Syntax:

<tuple variable name>._<Number of variable which we want to access in tuple>

Example of Tuples and Use

object TuplesExample {
def main(args: Array[String]): Unit = {
val myDetail = (10, "Jonny")
val myAddress = ("ZZZ Street", "XYZ City", "ABC Country")
println("Tuples values myDetail: "+myDetail._1 +" "+myDetail._2)
println("Tuples values myAddress: "+myAddress._1 +" "+myAddress._2+" "+myAddress._3)
  }
}

References

Reference from Scala org: Variables

Scala Classes and Objects

Tutorials Hut

Scala tutorials