C comparing pointers (with chars)

Question

Good evening, I have 2 functions and each of them accepts as argument a pointer to char:

char pointer[255];
func1(char* pointer)
{
...
memcpy(pointer,some_ch         


        

Answer 1

Well right off the bat, if you want to compare the pointees, you need to dereference them. This means to compare the actual char value, you'll have to call

if (*pointer == someother_char)

However this will only compare the first char in the array, which is probably not what you want to do.

To compare the whole thing strcmp should work

char* someother_str = "hello strstr";
if(strcmp(pointer, someother_str) == 0) {
    // do something
}

Make sure your other string is declared as a char*

More info: http://www.cplusplus.com/reference/clibrary/cstring/strcmp/

Edit: as per your comment. comparing char* and char doesn't really make sense. One is a character value, the other is an address in memory. Do do so, you can either dereference the char* or reference the value variable.

char c;
char* ptr;

// dereference ptr
if ( c == *ptr ) {
   ...
}

// reference the value
if ( &c == ptr ) {

}

The first method checks if the values are the same. The second checks if ptr is in fact pointing to the memory containing c ie. is ptr a pointer to c

Hope that helps