JavaOO-07.面向对象基础.ppt

IT Education 对象在程序执行时可以被创建和删除 IT Education 03 int doorNumber; 04 double topSpeed; 05 06 public void speedUp() 07 08 public void speedDown() 09 10 public void brake() 11 12 IT Education 03 int age; 04 double height; 05 06 public void sayHello() 07 System.out.println(“Hello“); 08 09 IT Education 类名 对象名 内存分配操作符 与类同名 Person q = new Person(); IT Education 04 =“zhangsan“; 05 p.age=33; 06 p.height=1.73; 07 p.sayHello(); 08 Person q = new Person(); 09 =“lisi“; 10 q.age=44; 11 q.height=1.74; 12 q.sayHello(); 13 14 IT Education 03 int age; 04 double height; 05 06 public Person( String n,int a, double h) 07 name=n; 08 age=a; 09 height=h; 10 11 12 public void sayHello() 13 System.out.println(“Hello, my name is “+name); 14 15 IT Education 0x8000 1.74 44 “lisi” Person p 0x8000 name age height IT Education Person q = new Person( “lisi”, 44,1.74); 0x8000 0x3000 1.74 44 “lisi” Person p 0x3000 name age height 1.73 33 “zhang”name age height Person q 0x8000 IT Education l IT Education 03 private int age; 04 private double height; 05 06 public Person(String name, int age) 07 = name; 08 this.age = age; 09 10 public void sayHello() 11 System.out.println(“Hello, my name is “+name); 12 13 IT Education p = null; u 一次性使用的匿名对象;new Person( ).sayHello( ); u 超出生命周期的；如： for( int I = 0; i 100; i+) Person p = new Person( ); 这里，变量p 被实例化100次，每结束一次循环，变量p就超出生命周期，对象变为垃圾。 IT Education o2 = null; Object o1 = new Object( ); o1 object The heap 检查出对象没有引用指 向 调用o2对象的finalize() 方法 垃圾回收机制回收分配 给该对象的内存 垃圾回收采用Java多线程机制 o2 object IT Education & Training Question And Answ