In Pascal language, sizeof () is a memory capacity measurement function, whose function is to return the size of a variable or type (in bytes); In C language, sizeof () is an operator to judge data type or expression length.
In Pascal and C languages, the processing of sizeof () is carried out in the compilation stage.
Related definition
Sizeof is an operator in C/C++. Simply put, its function is to return the number of memory bytes occupied by an object or type.
The explanation of MSDN is:
Sizeof keyword gives the amount of storage associated with a variable or type (including aggregate type), in bytes. This keyword returns a value of type size _ t.
Its return value type is size_t, which is defined in the header file stddef.h