Kotlin Constructors
Kotlin Constructor
In the previous chapter, we created an object of a class, and specified the properties inside the class, like this:
Example
class Car {
var brand = ""
var model = ""
var year = 0
}
fun main() {
val c1 = Car()
c1.brand = "Ford"
c1.model = "Mustang"
c1.year = 1969
}
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In Kotlin, there's a faster way of doing this, by using a constructor.
A
constructor is like a special function, and it is defined by using two parantheses ()
after the class name. You can specify the properties inside of the parantheses (like passing
parameters into a regular function).
The constructor will initialize the properties when you create an object of a class. Just remember to specify the type of the property/variable:
Example
class Car(var
brand: String, var model: String, var year: Int)
fun main() {
val c1 = Car("Ford",
"Mustang", 1969)
}
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Now it's even easier to specify multiple objects of one class:
Example
class Car(var
brand: String, var model: String, var year: Int)
fun main() {
val c1 = Car("Ford",
"Mustang", 1969)
val c2 = Car("BMW",
"X5", 1999)
val c3 = Car("Tesla",
"Model S", 2020)
}
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