{
private String s;
private String t;
Soap()
{
System.out.println("Soap()");
s = new String("Constructed");
t = new String("hello");
}
public String toString() { return t; }
}
public class Bath
{
Soap castille;
Bath()
{
castille=new Soap();
}
void print()
{
System.out.println("castille = " + castille);
}
public static void main(String[] args)
{
Bath b = new Bath();
b.print();
}
}
我上面的方法,是不是重定了那个toString方法.打印出来的是castille=hello;还有为什么会自动调用toString方法?
如果把上面的方法去掉,打印出的是 Soap@c17164 这个是对象是什么啊?
默认的toString方法里面返回的是什么,还是void???????????
[此贴子已经被作者于2007-6-29 17:15:14编辑过]
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上面是你的完整程序吗？castille没有定义额？
对于toString()是从Object中继承下来的，当然你也可以覆盖，他返回的String类型，
是关于该类的信息之类的
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不好意思,一时大意,给写少了.就不明白为什么会自动调用,还有后面是对象的什么信息?
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还有如果把
Bath()
{
castille=new Soap();
}
构造方法去掉,castille为null;这又是为什么呢?
----------------解决方案--------------------------------------------------------
System.out.print();中的参数是对象时会自动调用对象的toString()方法
以下是在JDK1.6文档中的注释
public String toString()
Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.
The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
Returns:
a string representation of the object.
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Soap@c17164 这里c17164应该就是上面所说的Soap的hashCode，
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谢谢啊,我还是看看API文档,英语不好.
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