指针算是一个比较常见，也是比较重要的知识点，大部分人都只是停留在表面的认识，今天转载逍遥整理的一篇文章，通俗易懂的描述了关于指针相关的内容。 #define NULL (void *)0 // 这里对应C语言的情况 #endif 编译器预先定义了一个宏_cplusplus，来判断当前的编译 ...

A value in a field or variable that indicates nothing was ever derived and stored in it. For example, in a decimal-based amount field, a null value might be all binary 0s (null characters), but not a ...

Null Hypothesis: The null hypothesis is a foundational concept in statistical hypothesis testing. It represents the assumption of no effect, no difference, or no relationship between variables. It ...