Question

void say(char msg[])
{   // using pointer to print out the first char of string
    printf("%c\n", *msg);
}

void say(char msg[])
{   // using pointer to print out the memory address of the         first char of string
    printf("%p\n", msg);
}

void say(char msg[])
{   // using pointer to print out the whole string
    printf("%s\n", msg);
}

The first two make sense, but I don’t quite understand how the third function works. All I know is that msg points to the memory address of the first character of the string. Thanks in advance.

Answer 1

%s will interpret the address of msg as the base addresss of a C string, which is a NULL terminated ('\0') sequence of bytes, and therefore the printf with the %s will take the base address of msg and print the character equivalent of each byte starting from msg and proceeding until it does not encounter a NULL character.