null == object和object == null之间的区别 [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？

当我检查 object.getItems == null 。
但是如果我把它改为 null == object.getItems（），它工作得很好。

我曾经调查过这个 null ！= object and object！= null
但我没有得到满意的答案。

解决方案

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

null == object and object == null

没有语义上的差异。

object.getItems（）== null 和 null == object.getItems（） p>

也许你正在混淆的是

  nonNullObj。 equals（obj）
  

和

  obj.equals（nonNullObj）
  

第二选择可以导致NPE，以防被调用者为空）。

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

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

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

解决方案

^{(Similar question: Which is more effective: if (null == variable) or if (variable == null)?)}

Difference between null==object and object==null

There is no semantical difference.

object.getItems() == null and null == object.getItems() are equivalent.

Perhaps you're mixing it up with the fact that

nonNullObj.equals(obj)

and

obj.equals(nonNullObj)

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

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