c++ - How to understand foo(char (&p)[10])? -

#include <iostream>  void foo(char (&p)[10]) {     printf("%d\n", sizeof(p)); }  char p[10] = "aaa";  int main() {     foo(p); } 

that code output 10, can't understand.

what meaning of char (&p)[10] here?

the argument function foo reference (&) char array of 10 elements (char ... [10]). name of argument p. reference means specify argument as-is (no pointer or address needed), calling foo(p) in main correct way given how p declared. function foo prints 10 because argument 10 bytes in size.