System.out.println(new Integer(1).equals(new Long(1)));为什么是这个答案？？？？？

[wenjjing2lianee]

System.out.println(new Integer(1).equals(new Long(1)));
为什么是这个答案？？？？？

[ty_fzpb]

你读一下equals源代码就知道了……

[zhj92lxs]

/**
* Compares this object to the specified object. The result is
* <code>true</code> if and only if the argument is not
* <code>null</code> and is an <code>Integer</code> object that
* contains the same <code>int</code> value as this object.
*
* @param obj the object to compare with.
* @return <code>true</code> if the objects are the same;
* <code>false</code> otherwise.
*/
public boolean equals(Object obj) {
if (obj instanceof Integer) {
return value == ((Integer)obj).intValue();
}
return false;
}



这是Integer对equals 方法的重写，看看就知道了

[ahlon]

[Quote=引用 2 楼 zhj92lxs 的回复:]
/**
* Compares this object to the specified object. The result is
* <code>true </code> if and only if the argument is not
* <code>null </code> and is an <code>Integer </code> object that
* contains the same <code>int </code> value as this object.
*
* @param obj the object to compare with.
* @return <code>true </code> if the objects are the same;
…
[/Quote]
对，是由于Integer类的equals方法决定的

[wenjjing2lianee]

谢谢各位!!!!!

[andyheway]

public boolean equals(Object obj)
{
if(obj instanceof Integer)
return value == ((Integer)obj).intValue();
else
return false;
}
正解。直接就是false。