qsort() 函数如何工作？

Question

void qsort (
    void* base,
    size_t num,
    size_t size,
    int (*compar)(const void*,const void*)
);

How qsort function access "size" byte after adress to get next element?
By typecasting void* to char* ?

Answer 1

How does the qsort function access "size" bytes after the base address to get the next element? By typecasting void* to char* ?

The assumption inherent in the question is that qsort is itself written in C; it need not be. Let's assume that it is.

A conversion to char* would be a typical way of doing it, yes, either by explicitly using a cast operator, or by assigning base to a local variable of type char* .

GNU C allows you to add an integer to a void pointer directly, but that is a non-portable extension to the C language.

If you have a question about a specific implementation, say what implementation.