val and var

Kotlin has two keywords for declaring variables, val and var. The var variable is a mutable variable, that is, a variable that can be changed to another value by reassigning it. This is equivalent to declaring a variable in Java:

    var name = "kotlin" 

In addition to this, the var variable can be initialized later:

    var name: String 
    name = "kotlin" 

Variables defined with var can be reassigned, since they are mutable:

    var name = "kotlin" 
    name = "more kotlin" 

The val keyword is used to declare a read-only variable. This is equivalent to declaring a final variable in Java. A val variable must be initialized when it is created, since it cannot be changed later:

    val name = "kotlin" 

A read-only variable does not mean the instance itself is automatically immutable. The instance may still allow its...