JuniorTheoryCommon

What does the program print (lines separated by spaces)?

KOTLIN

class Box(val size: Int) {
    init { println("init $size") }
    val double = size * 2
    init { println("double $double") }
}

fun main() {
    Box(3)
}

init 3 double 6

Expecting double 6 init 3: thinking properties are set before any init runs. Initializers and init blocks run top to bottom, in the order they are written.
Expecting double 0: thinking every init runs before any property. double = size * 2 sits between the two blocks, so the second init reads 6.

What changes if val double is moved below the second init block?
How many init blocks may one class have?

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Back to questions

JuniorTheoryCommon

What does the program print (lines separated by spaces)?

KOTLIN

class Box(val size: Int) {
    init { println("init $size") }
    val double = size * 2
    init { println("double $double") }
}

fun main() {
    Box(3)
}

init 3 double 6

Expecting double 6 init 3: thinking properties are set before any init runs. Initializers and init blocks run top to bottom, in the order they are written.
Expecting double 0: thinking every init runs before any property. double = size * 2 sits between the two blocks, so the second init reads 6.

What changes if val double is moved below the second init block?
How many init blocks may one class have?

Back to questions Open topic in roadmap →Answer it yourself — Quiz