Kotlin OOP : Constructor
Welcome to kotlin Series
Kotlin OOP series:
This is the second post about Kotlin OOP Concept. In the previous post, Kotlin OOP: Basic
we talk about a basic opp concept.
In this post, we are going to litter deeper.
Let's start-
From the previous post, we create an Apple class like previous.
let do this-
This is a very smaller post. In this post we cover constructor. Some you need the secondary constructor and some time you need the primary constructor. If you come from Java then you should go through the secondary constructor. Then it looks link java. So you feel easy to learn Kotlin. Keep learning.
Thank you for reading this post.
Happy coding.
Kotlin OOP series:
This is the second post about Kotlin OOP Concept. In the previous post, Kotlin OOP: Basic
we talk about a basic opp concept.
In this post, we are going to litter deeper.
Let's start-
From the previous post, we create an Apple class like previous.
let do this-
private class Apple(color:String,shape:String){ var color:String? = null var shape:String? = null init { //println("Color: $color") //println("Shape: $shape") this.color = color this.shape = shape } fun GetColor():String?{ return this.color } fun GetShape():String?{ return this.shape } }In this class, we are working with the primary constructor. But If we have another option to working with the second constructor. Just like Java. How can I do this? Let's start- Let's make the primary constructor empty
private class Apple3(){ }and declarer secondary constructor like below-
constructor(color:String,shape:String): this() { }Now declare class two class variable and assign it in the constructor.
var color:String? = null var shape:String? = nullassign it-
//second constrictor constructor(color:String,shape:String): this() { this.color = color this.shape = shape }Greater and setter method already there Check full class code-
private class Apple(){ var color:String? = null var shape:String? = null //second constrictor constructor(color:String,shape:String): this() { this.color = color this.shape = shape } fun GetColor():String?{ return this.color } fun GetShape():String?{ return this.shape } }test this on the Main method-
fun main(args: Array<String>){ val apple =Apple3("red","oval") println("Color: ${apple.GetColor()} Shape: ${apple.GetShape()}") }output-
Color: red Shape: ovalThis is very similar to Java code. But if you are using this secondary constructor. you can not create a variable like the primary constructor.
This is a very smaller post. In this post we cover constructor. Some you need the secondary constructor and some time you need the primary constructor. If you come from Java then you should go through the secondary constructor. Then it looks link java. So you feel easy to learn Kotlin. Keep learning.
Thank you for reading this post.
Happy coding.
No comments :