How are arrays passed in C++ by reference or value or by pointer?

问题

I am a beginner trying to learn C++. Apologies if my question is not structured properly? I was working with arrays and found out that I can manipulate the values stored in an array through a function without using the & or pass by reference sign. I don't understand how this is possible as the lack of & sign means that it is passed by value and a copy is made which is manipulated.

Elsewhere, I read that arrays are passed by pointers if this is the case I didn't use any explicit dereferencing to manipulate the data. Can you please explain what is actually happening when I pass an array?

Side note: Why is it that I have to specify column size when passing a 2D array into a function?

回答1:

C-array decays to pointer.

Some declarations are misleading too

void foo(const char name[42]);

is in fact

void foo(const char* name);

Only reference/pointer (ugly syntax :/) allow to keep size:

void foo(const char (&name)[42]);
void foo(const char (*name)[42]);

来源：https://stackoverflow.com/questions/44696363/how-are-arrays-passed-in-c-by-reference-or-value-or-by-pointer