Kotlin : lateinit keyword vs lazy delegation (Post 21)

Hi ,

Here is my last topic of this Kotlin Basic Series . In this post I will talk about lateinit keyword & lazy delegation

lateinit keyword : 

It is used at the time of variable declaration , there are some rules :

• It is used with mutable type of variables i.e. var
• lateinit var name : String  ------  Allowed
• lateinit val name : String  ------ Not Allowed

• Allowed only non-nullable data types 
• lateinit var name : String  ------  Allowed
• lateinit val name : String?  ------ Not Allowed

• The value must be assigned before it is used , other it throws UnintializedPropertyAccessException

lateinit var name : String

lazy Delegation :

lazy is lazy initialization.

lazy() is a function that takes a lambda and returns an instance of lazy which can serve as a delegate for implementing a lazy property:

• The first call to get() executes the lambda passed to lazy() and remembers the result, subsequent calls to get() simply return the remembered result.
• It is thread safe , it is initialized in thread where it is used for the first time , other threads used the same value remembered result which is stored in cache . 
• It can be used with var & val both
• It can be used with nullable & non-nullable values both 

public class Example{
  val name: String by lazy { "Android" }
}

So that's it  for this post and for this series as well . I tried to explore and cover all the basic topics of Kotlin here, and with the help of these topics one can understand and develop android applications in Kotlin as well .

In next post , I will explore a very interesting & essential topic i.e. Accessibility , till then Happy Coding 😀😀