package quickanswer.chapter8
class Creature {
val range: Int = 10
val env: Array[Int] = new Array[Int](this.range)///calls the range() 方法而不是对字段的的直接引用 和java 的区别
}
class Ant extends Creature {
override val range = 2
}
object ConstructionOrder extends App {
val ant= new Ant
println(ant.range);
println(ant.env.length);
}
?package quickanswer.chapter8;
class CreatureJava {
int range=10;
int[] env = new int[range];
public int getRange() {
return range;
}
}
class AntJava extends CreatureJava {
int range = 2;
@Override
public int getRange() {
return range ;
}
}
public class ConstructionOrderJava {
public static void main(String[] args) {
AntJava a=new AntJava();
System.out.println(a.range);
System.out.println(a.env.length);
}
}
?public class Creature
{
public int range()
{
return this.range;
}
private final int range = 10;
public int[] env()
{
return this.env;
}
private final int[] env = new int[range()];
}
?1. The?Ant?constructor calls the?Creature?constructor before doing its own construction.
2. The?Creature?constructor sets?its?range?field to?10.
3. The?Creature?constructor, in order to initialize the?env?array, calls the?range()?getter.
4. That method is overridden to yield the (as yet uninitialized)?range?field of the?Ant?class.
5. The?range?method returns?0. (That is the initial value of all integer fields when an object is allocated.)
6.?env?is set to an array of length?0.
7. The?Ant?constructor continues, setting its?range?field to?2.
?
原文：http://zhouchaofei2010.iteye.com/blog/2253923