Java变量作用域与生命周期

public class A {

private int a;

public A(int a) {this.a= a;}

protected void finalize() {System.out.println("开始清理对象"+a);}

}

（1）public class Test1 {

public static void main(String[] args) {

{

A a = new A(1);

A aa = new A(11);

}

System.gc();

}

}

无输出结果

================================================

（2）public class Test2 {

public static void main(String[] args) {

{

A a = new A(1);

A aa = new A(11);

}

{

A a = new A(2);

}

System.gc();

}

}

输出结果：

开始清理对象1

===================================================

（3）public class Test3 {

public static void main(String[] args) {

{

A a =new A(1);

A aa =new A(11);

}

{

A a =new A(2);

A aa =new A(22);

}

System.gc();

}

}

输出结果：

开始清理对象11

开始清理对象1

==================================================

（4）public class Test4 {

public static void main(String[] args) {

{

A a =new A(1);

A aa =new A(11);

}

{

A a =new A(2);

A aa =new A(22);

}

A a =new A(3);

System.gc();

}

}

输出结果：

开始清理对象2

开始清理对象11

开始清理对象1

=================================================

（5）public class Test5 {

public static void main(String[] args) {

{

A a =new A(1);

A aa =new A(11);

}

{

A a =new A(2);

A aa =new A(22);

}

A a =new A(3);

A aa =new A(33);

System.gc();

}

}

输出结果：

开始清理对象22

开始清理对象2

开始清理对象11

开始清理对象1