null==object 和 object==null 的区别 [英] Difference between null==object and object==null

问题描述

我想知道上述比较之间的差异?

Hi I would like to know diff between the above comparisons?

当我检查 object.getItems() == null 时，我得到空指针异常.但是如果我将其更改为 null == object.getItems()，它就可以正常工作.

I am getting null pointer exception when I check object.getItems() == null. But if I change it to null == object.getItems(), it workes fine.

我确实研究过这个有什么区别在 null != object 和 object!=null 之间但我没有得到满意的答复.

I did look into this what is the difference between null != object and object!=null But I didnt get satisfactory answer.

推荐答案

^{(类似问题:哪个更有效:if (null == variable) or if (variable == null)?)}

null==object 和 object==null 的区别

Difference between null==object and object==null

没有语义差异.

object.getItems() == null 和 null == object.getItems() 是等价的.

也许你把它与

nonNullObj.equals(obj)

和

obj.equals(nonNullObj)

可以有所作为(因为如果被调用者为空，第二种选择可能会导致 NPE).

can make a difference (since the second alternative could result in a NPE in case the callee is null).

这篇关于null==object 和 object==null 的区别的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！