Why do we need argc while there is always a null at the end of argv?

Question

It seems that the argv[argc] is always NULL, so I think we can traverse the argument list without argc. A single while lo

Answer 1

Yes, argv[argc] is guaranteed to be a null pointer. argc is used for convenience.

Quoting the official explanation from C99 Rationale, note the words redundant check:

Rationale for International Standard — Programming Languages — C §5.1.2.2.1 Program startup

The specification of argc and argv as arguments to main recognizes extensive prior practice. argv[argc] is required to be a null pointer to provide a redundant check for the end of the list, also on the basis of common practice.