Access Modifiers in Scala

Access Modifiers in scala are used to define the access field of members of packages, classes or objects in scala.For using an access modifier, you must include its keyword in the definition of members of package, class or object.These modifiers will restrict accesses to the members to specific regions of code. There are Three types of access modifiers available in Scala:

1. Private
2. Protected
3. Public

Table:

Modifier	Class	Companion	Subclass	Package	World
No Modifier/Public	Yes	Yes	Yes	Yes	Yes
Protected	Yes	Yes	Yes	No *	No
Private	Yes	Yes	No	No *	No

What is companion in above table? It is a singleton object named same as the class. 1. Private: When a member is declared as private, we can only use it inside defining class or through one of its objects. Example: Scala

// Scala program of private access modifier
class abc
{ 
    private var a:Int = 123
    def display()
    {
        a = 8
        println(a)
    }
}

object access extends App
{
    // class abc is accessible 
    // because this is in the same enclosing scope
    var e = new abc()
    e.display()
}

Output:

8

Here we declared a variable 'a' private and now it can be accessed only inside it's defining class or through classes object. 2. Protected: They can be only accessible from sub classes of the base class in which the member has been defined. Example: Scala

// Scala program of protected access modifier

class gfg
{ 
    // declaration of protected member
    protected var a:Int = 123
    def display()
    {
        a = 8
        println(a)
    }
}

// class new1 extends by class gfg
class new1 extends gfg
{
    def display1()
    {
        a = 9
        println(a)
    }
}

object access extends App
{
    // class abc is accessible because this
    // is in the same enclosing scope
    var e = new gfg()
    e.display()
    var e1 = new new1()
     e1.display1()
        
}

Output:

8
9

When we extended abc in class new1, protected variable a is now available to be modified cause new1 is a subclass of class abc. 3. Public: There is no public keyword in Scala. The default access level (when no modifier is specified) corresponds to Java’s public access level.We can access these anywhere. Scala

// Scala program of protected access modifier

class gfg
{
    var a:Int = 123
}
object access extends App
{
    var e = new gfg()
    e.a = 444    
    println(e.a)
}

Output:

444