Variables and Types
Scala is statically typed, so variable types are known at compile time. However, Scala also supports type inference in variable declaration.
The basic types in Scala are:
ByteShortIntLongFloatDoubleCharStringBoolean
Numbers
To declare and assign a number in Scala, you can use the following syntax:
val myNumber: Int = 5
You can also use type inference:
val myNumber = 5
For floating-point numbers an 'f' suffix is needed to specify that it is a float:
val d: Double = 4.5
val f: Float = 4.5f
Characters
A character is defined using single quotes:
val c: Char = 'g'
Strings
A string is defined using double quotes:
val s: String = "Hello, world!"
Booleans
A boolean is defined as either true or false:
val b: Boolean = true
Val and Var
Variables in Scala are either declared using val or var.
Any variables declared using val are immutable and cannot be changed once assigned, but variables declared with var are mutable and can be changed after assignment.
In this case, the value of pi will not change, so we should declare it using val:
val pi: Double = 3.14159
While in this case, the value of counter may change, so we should declare it with var:
var counter: Int = 0
Exercise
Define variables with the following values:
A string named productName equal to "Laptop".
An integer named productYear equal to 2023.
A double named productPrice equal to 999.99.
Sponsors
