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  • 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.

    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

    Next Articles

    • Scala Classes and Objects

















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