what is the value of null in c
Null pointer In C, two null pointers of any type are guaranteed to compare equal.[1] The preprocessor macro NULL is defined as an implementation-defined null pointer constant,[2] which in C99 can be portably expressed as the integer value 0 converted implicitly or explicitly to the type void* (pointer to void).[3] The C standard does not say that the null pointer is the same as the pointer to memory addressÂ 0, though that may be the case in practice. Dereferencing a null pointer is undefined behavior in C, and a conforming implementation is allowed to assume that any pointer that is dereferenced is not null.
Blank (solution) A blank solution is a solution containing little to no analyte of interest,[1] usually used to calibrate instruments such as a colorimeter. According to the EPA, the "primary purpose of blanks is to trace sources of artificially introduced contamination."[2] Different types of blanks are used to identify the source of contamination in the sample. The types of blanks include equipment blank, field blank, trip blank, method blank, and instrument blank.[3]