This marker is usually called the null value, the null list, or the null pointer. 这个标记通常称作空值(nullvalue)、空列表(nulllist)或者空指针(nullpointer)。
That means a reference type can have a null pointer, but a value type cannot have a null value. 这意味着引用类型可能有空指针,但是数值类型不能有空值。
This function returns a pointer to the value in the environment or NULL if there is no match. 这个函数会返回一个指向环境中的值的指针,或者如果不匹配则返回NULL。
The return value is a pointer to the buffer allocated for the message. A NULL return indicates the message allocation operation failed. 返回值是为信息分配的缓冲区的指针。如果是NULL表明信息分配操作失败。
A prototype tool has been developed. It integrates three typical data flow analysis techniques: null pointer dereference analysis, integer variable value interval analysis and the single-linked list reachability analysis, and offer the ability to interact with users. 本文实现了一个分析工具原型,它将空指针解引用分析技术、整型变量取值范围分析技术、单链表可达性分析技术整合到一起,并允许使用者进行人工干预。