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Kotlin program | Example of Various Visibility Modifiers

Kotlin | Various Visibility Modifiers: Here, we are implementing a Kotlin program to demonstrate the example of various visibility modifiers.
Submitted by IncludeHelp, on June 12, 2020

Visibility Modifiers

• Visibility modifiers are that set the accessibility (visibility) of Classes, objects, interfaces, constructors, functions, properties, and their setters.
• There are four types of visibility modifiers,
  1. Public
  2. Private
  3. Protected
  4. Internal
• Getters always have the same visibility as the properties.
• Visibility modifiers for members declared inside class and interfaces,
  1. public: Vsible to any client who can see declaring class.
  2. private: Visible inside the class only.
  3. protected: Visible inside the class(same as private) and visible in subclasses too.
  4. internal: Visible to any client inside the module who can see declaring class.
• Local variables, functions, and classes can not have visibility modifiers.
• To specify the visibility of the primary constructor of a class, use the following syntax (by default constructors are public),

  class C private constructor(a: Int) { ... }
  

Program to demonstrate the example of Various Visibility Modifiers in Kotlin

package com.includehelp

// Class, by default public visibility
// Mark with 'open' to make inheritable
open class MyOuter{
    private var myname="IncludeHelp India !!"
    protected open val age=30
    internal var salary=100

    var city="Delhi"  // Public , by default

    protected fun fun1(){
        println("Protected Function in Base !!")
    }
}

class MySub: MyOuter() {
    // Override protected members, 
    // because protected is visible in subclass
    override val age: Int
        get() = 50

    fun printDetails(){
        // Can't Access $myname as it is private in super class
        // println("Name :  $myname")

        println("City :  $city")
        println("Salary : $salary")
        println("Age : $age")
    }
}

// Main function, Entry Point of Program
fun main(){
    // Create Instance
    val myOuter = MySub()
    // Call subclass method
    myOuter.printDetails()
}

Output:

City :  Delhi
Salary : 100
Age : 50