Kotlin - Class & Objects

Kotlin supports both Object Oriented and Functional Programming As we know in Object Oriented Program, class is nothing but a blue print of an entity, where as Object is its State. Object inclused state and behaviour of state.

Class ClassA
{
    // class Body
 }

Let's check below examples

How do i create a class object in Kotlin

Car is an Object

Where State of Car are

Speed
Gear
Behaviours are
Change Gear
Go fast/slow

class Car {

// property (data member)
private var Speed: Int = 30

// member function
fun goSpeed() {
 Speed = 60
}

// member function
fun goSlow() {
 Speed = 20
}
}

In above we created a class with name Car

Car contains property is speed and we can change the behavoiur of the car by memeber functions
goSpeed() and goSlow()

Object Creation

When we created a class, to access/update the state/behaviour of the class we need to create an object to that class

We can check below how to create an object

class Car {

// property (data member)
private var Speed: Int = 30

// member function
fun goSpeed() {
Speed = 60
}

// member function
 fun goSlow() {
     Speed = 20
 }
}
fun main(args:Array){
    val obj=Car()
}
                                

Here obj is object for the class Car, create object by calling the call with open close braces
(Car())

Like java, in kotlin not required new key word