Java-Initialization
- package interfaces.music;
- abstract class Base{
- Base(){
- print();
- }
- public abstract void print();
- }
- class Derived extends Base{
- private int i = 1;
- public void print() {
- System.out.println(i);
- }
- }
- public class E03_Initialization {
- public static void main(String[] args) {
- Derived d = new Derived();
- d.print();
- }
- }
首先寻找main函数,进入main函数;
执行 Derived d = new Derived();
加载 class Derived extends Base,发现有一个父类;
加载父类Base;
父类Base有个一构造函数,执行构造函数;
构造函数中有个print方法,此方法被子类print方法覆盖,但此时子类方法中 i=1 未被加载,因此系统默认给 i 赋值为0,故此时会执行子类print方法,打印出 0;
加载子类Derived;
执行d.print,打印出 1;
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