Scala Variables and Data Types

Category : Scala | Sub Category : Scala Programs | By Prasad Bonam Last updated: 2023-10-10 04:21:57 Viewed : 274

In Scala, you can define variables using either var (mutable variables) or val (immutable variables). Scala also has a rich set of data types. Here are examples of variables and data types in Scala:

Variables (var and val):

1. Mutable Variable (var):

   scalaCopy code
   var counter = 0 // Mutable variable
   counter = 1     // Variable value can be changed
   

   Mutable variables can be changed after they are initialized.

2. Immutable Variable (val):

   scalaCopy code
   val pi = 3.14159 // Immutable variable
   // pi = 3.14     // Error: Reassignment to val is not allowed
   

   Immutable variables cannot be reassigned once they are initialized. This encourages functional programming and safer code.

Data Types:

Scala has various data types, including numeric types, characters, strings, booleans, and more. Here are some examples:

1. Numeric Types:

   • Integers:

     scalaCopy code
     val age: Int = 30
     

   • Floating-Point Numbers:

     scalaCopy code
     val price: Double = 19.99
     

   • BigInt and BigDecimal (for Arbitrary Precision):

     scalaCopy code
     val bigValue: BigInt = BigInt("1234567890123456789012345678901234567890")
     val bigDecimalValue: BigDecimal = BigDecimal("1234.56789012345678901234567890")
     

2. Characters and Strings:

   • Characters (Char):

     scalaCopy code
     val firstLetter: Char = `A`

   • Strings (String):

     scalaCopy code
     val greeting: String = "Hello, Scala!"
     

3. Booleans:

   scalaCopy code
   val isTrue: Boolean = true
   val isFalse: Boolean = false
   

4. Collections:

   Scala provides various collections, including Lists, Sets, Maps, and more. Here is an example with a List:

   scalaCopy code
   val fruits: List[String] = List("Apple", "Banana", "Orange")
   

5. Tuples:

   Tuples allow you to group multiple values of different types:

   scalaCopy code
   val person: (String, Int) = ("Alice", 30)
   val (name, age) = person
   

6. Option:

   The Option type is used to represent values that might be absent (null in other languages):

   scalaCopy code
   val maybeValue: Option[Int] = Some(42)
   val absentValue: Option[Int] = None
   

   Some represents a value, while None represents absence.

7. Custom Types (Case Classes):

   You can define custom data types using case classes:

   scalaCopy code
   case class Person(name: String, age: Int)
   val alice = Person("Alice", 30)
   

8. Enums (Enumerations):

   Scala 3 introduces enums to define a fixed set of values:

   scalaCopy code
   enum Color:
     case Red, Green, Blue
   
   val color: Color = Color.Green
   

These are some of the commonly used data types and variable declarations in Scala. Scala is a statically typed language, so you typically specify the data type explicitly when declaring variables. However, Scalas type inference can often infer types, so you dont always need to provide explicit type annotations.