What are Scala variables, and how do we declare them? What is type inference? How do we perform multiple assignments? What is the variable scope? These are the questions we\u2019ll be answering today.<\/p>\n
So, let’s start Scala Variables Tutorial.<\/p>\n
A variable is a reserved memory location to store values. The compiler allocates memory and decides what goes in based on a variable\u2019s data type. We can assign different types like integers, characters, or decimals to variables. Let\u2019s begin.<\/p>\n
We can declare a Scala variable as a constant or as a variable:<\/p>\n
To declare a value that we cannot mutate\/change, we use the keyword \u2018val\u2019. This is immutable.<\/p>\n
val x:Int=7\r\nval name:String=\u201dAyushi\u201d<\/pre>\nb. Variable<\/h4>\n
A variable is mutable. We can change its value as many times as we like. Declare it using the keyword \u2018var\u2019.<\/p>\n
var name:String=\u201dAyushi\u201d\r\nname=\u201dMegha\u201d<\/pre>\nScala Variables Type Inference<\/h3>\n
When we assign an initial value to a variable, the compiler infers its type based on the types of the subexpressions and the literals. This means that we don\u2019t always have to declare the type of a variable.<\/p>\n
val x=1+2\r\nvar name=\u201dAyushi\u201d<\/pre>\nScala Variable Data Types<\/h3>\n
We can specify a variable\u2019s type after a colon after its name. Take an example:<\/p>\n
val x:Int=7\r\nval x:Int<\/pre>\nMultiple Assignments<\/h3>\n
How do we fit multiple assignment statements into one statement? We assign a Tuple to a val variable.<\/p>\n
val (x: Int, y: String) = Pair(7, \"Ayushi\")\r\nval (x, y) = Pair(7, \"Ayushi\")<\/pre>\nScala Variable Scope<\/h3>\n
We have three kinds of scopes for Scala variables. Let\u2019s see them one by one.<\/p>\n
a. Fields<\/h4>\n
If an object owns a variable, the variable is a field in it. We can access fields from inside every method in the object. Well, we can also access them outside the object if we declared them with the right access modifiers. A field may be mutable or immutable, and we can define them using \u2018var\u2019 or \u2018val\u2019.<\/p>\n
b. Method Parameters<\/h4>\n
A method parameter is a variable that we can use to pass a value inside a method when we call it. We can only access it inside the method, but if we have a reference to that object from outside the method, we can access the objects from outside. A method parameter is always immutable, and we define it using the \u2018val\u2019 keyword.<\/p>\n
c. Local Variables<\/h4>\n
A local variable is one we declare inside a method. While we can only access it from inside a method, if we return the objects, that we create, from the method, they may escape it. A local variable may be mutable or immutable, and we may define it using the keywords \u2018var\u2019 or \u2018val\u2019.<\/p>\n
So, this was all about Scala Variables. Hope you like our explanation.<\/p>\n
Conclusion<\/h3>\n
Hence, we discussed about\u00a0how to declare Scala variables, type inference, data type, and scope. If you have any query regarding Scala Variables, please comment. See you again with another topic to learn with Scala. Have a good day.<\/p>\n