避免！=空語句 - Avoiding != null statements

問題：

I use object != null a lot to avoid NullPointerException . 我常用object != null來避免NullPointerException 。

Is there a good alternative to this? 有沒有好的替代方法？

For example: 例如：

if (someobject != null) {
    someobject.doCalc();
}

This avoids a NullPointerException , when it is unknown if the object is null or not. 若是不知道對象是否爲null ，則能夠避免NullPointerException 。

Note that the accepted answer may be out of date, see https://stackoverflow.com/a/2386013/12943 for a more recent approach. 請注意，接受的答案可能已過時，請參閱https://stackoverflow.com/a/2386013/12943以獲取最新的方法。

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解決方案：

參考一： https://stackoom.com/question/18dS/避免-空語句
參考二： https://oldbug.net/q/18dS/Avoiding-null-statements