package wzs.test2;
//将一个对象赋值给另一个对象,实际是将引用从一个地方复制到另一个地方
//这意味着,如果对象tank1=tank2,那么tank1和tank2都指向原本只有tank2指向的那个对象
//为了避免这种问题,应该tank1.level=tank2.level
public class Test_wzs2
{
public static void main(String[] args)
{
Tank tank1 = new Tank();
Tank tank2 = new Tank();
tank1.level = 1;
tank2.level = 2;
System.out.println("tank1.level=" + tank1.level + ", tank2.level=" + tank2.level);
tank1 = tank2;
System.out.println("tank1.level=" + tank1.level + ", tank2.level=" + tank2.level);
tank1.level = 5;
System.out.println("tank1.level=" + tank1.level + ", tank2.level=" + tank2.level);
tank2.level = 7;
System.out.println("tank1.level=" + tank1.level + ", tank2.level=" + tank2.level);
// ----------------------------
Tank tank3 = new Tank();
Tank tank4 = new Tank();
tank3.level = 1;
tank4.level = 2;
tank3.level = tank4.level;
System.out.println("\ntank3.level=" + tank3.level + ", tank4.level=" + tank4.level);
tank3.level = 7;
tank4.level = 8;
System.out.println("tank3.level=" + tank3.level + ", tank4.level=" + tank4.level);
}
}
class Tank
{
int level;
}
输出结果:
tank1.level=1, tank2.level=2
tank1.level=2, tank2.level=2
tank1.level=5, tank2.level=5
tank1.level=7, tank2.level=7
tank3.level=2, tank4.level=2
tank3.level=7, tank4.level=8