java子类实例初始化过程
子类的实例化主要分为两个步骤:
<1>.类相关静态内容初始化;
*先父类再子类:
? 1.父类的static属性;
? 2.父类的static块;
? 3.子类的static属性;
? 4.子类的static块;
<2>.类的实例内容初始化;
*调用构造子:先父类后子类:构造子调用之前先实例化实例字段和块
? 5.父类的普通属性;
? 6.父类的普通块;
? 7.父类的构造子;
? 8.子类的普通属性;
? 9.子类的普通块;
? 10.子类的构造子;
?
举例:
package basic;public class ClzInit {public static void main(String[] args) {new Son();}}class Parent {protected int n = 5;protected static int m = 5;static {m = m * 2;System.out.println("父类静态块调用;m="+m);}{n = n * 2;m = m * 2;System.out.print("父类普通块调用;");System.out.print("n="+n);System.out.println("m="+m);}public Parent() {this.n = n * 10;m = m + 10;System.out.print("父类构造子;n="+n);System.out.println("m="+m);}}class Son extends Parent {private int sn=3;private static int sm=3;static {m = m + 2;sm=sm+2;System.out.println("子类静态块调用;m="+m);}{n = n + 2;sn=sn+2;m = m + 2;System.out.println("子类普通块调用;");System.out.print("n="+n);System.out.print("sn="+sn);System.out.println("m="+m);}public Son() {this.n = n + 10;sn=sn+10;m = m + 10;System.out.print("子类构造子;n="+n);System.out.println("m="+m);}}?看输出结果,可见端倪:
父类静态块调用;m=10子类静态块调用;m=12父类普通块调用;n=10m=24父类构造子;n=100m=34子类普通块调用;n=102sn=5m=36子类构造子;n=112m=46
?备忘。欢迎各位指正!