Java是否允许可以为空的类型？ [英] Does Java allow nullable types?

问题描述

在C＃中我可以使用变量来允许带有问号的空值。我想要一个true / false / null结果。我希望默认情况下将其设置为null。测试结果将布尔值设置为true / false，但有时测试不会运行，并且java中的布尔值默认为false，因此测试的第3个选项会很好。

In C# I can a variable to allow nulls with the question mark. I want to have a true/false/null result. I want to have it set to null by default. The boolean will be set to true/false by a test result, but sometimes the test is not run and a boolean is default to false in java, so 3rd option to test against would be nice.

c＃例如：

bool? bPassed = null;

java有类似的东西吗？

Does java have anything similar to this?

推荐答案

否。

相反，你可以使用盒装布尔 class（普通类而不是原始类）或三值枚举。

Instead, you can use the boxed Boolean class (which is an ordinary class rather a primitive type), or a three-valued enum.

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