Trusted answers to developer questions
How to override a property in Kotlin
Shubham Singh KshatriyaOverview
Property overriding means redefining or modifying the property of the base class in its derived class. Thus, it can be only achieved in inheritance. The property that needs to be overridden should be open in nature, in the base class. We cannot override a method that is final in nature.
Syntax
To override a property of the base class in the derived class, we use the override keyword.
open class base {
open val value: Int = 5
}
class derived : base() {
override val value: Int = 10
}Syntax
Example
// base class
open class base {
open val value: Int = 5
}
// derived class
class derived : base() {
// overriding property value of base class
override val value: Int = 10
}
fun main() {
// instantiating base class
val b = base()
// printing property value of base class
println("Value in base class: ${b.value}")
// instantiating derived class
val d = derived()
// printing property value of derived class
println("Value in derived class: ${d.value}")
}Example of property overriding in Kotlin
Explanation
- Lines 2–4: We create a class
basewith a propertyvalue.
Note: We have marked the property
valueasopen.
- Line 7: We create a
derivedclass by inheriting thebaseclass. - Line 9: We use the
overridekeyword to override the propertyvalueof the base class.
Inside the main() function:
- Line 14: We instantiate an object of the
baseclass. - Line 16: We print the property
valueof thebaseclass objectbto the console.
- Line 19: We instantiate an object of the
derivedclass. - Line 21: We print the property
valueof thederivedclass objectdto the console.
Output
In the output, we can see that the value in base is 5, whereas the value in derived is 10. Thus, the property value of base is overridden in derived .
RELATED TAGS
kotlin
override property
communitycreator
CONTRIBUTOR
Shubham Singh KshatriyaRELATED COURSES
View all Courses
Keep Exploring
Related Courses
