java基础问题

Question

public class Flower {
private int petalCount = 0;
private String s = new String("null");
Flower(int petals) {
petalCount = petals;
System.out.println(
"Constructor w/ int arg only, petalCount= "
+ petalCount);
}
Flower(String ss) {
System.out.println(
"Constructor w/ String arg only, s=" + ss);
s = ss;
}
Flower(String s, int petals) {
this(petals);
//! this(s); // Can't call two!
this.s = s; // Another use of "this"
System.out.println("String & int args");
}
Flower() {
this("hi", 47);
System.out.println(
"default constructor (no args)");
}
void print() {
//! this(11); // Not inside non-constructor!
System.out.println(
"petalCount = " + petalCount + " s = "+ s);
}
public static void main(String[] args) {
Flower x = new Flower();
x.print();
}
} ///:~

请问一下上面的输出结果是什么,为什么!说明原因

Answer 1

我初看还以为是类的变量的初始化顺序呢.

这个, 不就是一层一层的调用this上去么. 再一层一层的回来. 没特别的地方呀.
输出顺序等于调用顺序, 再加上 调用结束回来继续向下的输出.

Constructor w/ int arg only, petalCount= 47
// this(petals);

String & int args
// this("hi", 47);

default constructor (no args)
// new Flower();

petalCount = 47 s = hi
// x.print();