looking at the string of characters in buffer for fgets

**laserlight** · 05-13-2019

You scored 1 out of 3. Fail!

**cooper1200** · 05-13-2019

one the first line (function deceleration) you declared the argument as int in main you declared the array as int (int xs[].....) so one can assume unless they aren't part of main that xs[0] or xs or &xs are of the same type surely
coop

**laserlight** · 05-13-2019

Ah, perhaps we have found a serious misunderstanding. In this function definition:

Code:

void foo(int *p) {}

The type of the parameter named p is not int. It is pointer to int, i.e., int*

In this declaration and initialisation of an array named xs:

Code:

int xs[] = {1, 2};

The type of xs is array of 2 ints, i.e., int[2]. The 2 ints is because of the initialisation to an aggregate containing 2 ints.

For foo(xs[0]), the type of the argument is an int. You know that foo expects an int*, so this is wrong.

For foo(xs), the type of the argument is int[2]. This can be converted to int* since when passed as an argument, an array is converted to a pointer to its first element, so this is correct.

For foo(&xs), the type of the argument is pointer to the array of 2 ints itself, i.e., int(*)[2]. Hence, this is wrong, even though the address would coincide with the address of the first element of xs.

Function pointers aside, it is never ever the case that xs[0], xs, and &xs have the same type.

**cooper1200** · 05-13-2019

ok so if i had an array

Code:

 int array[5] = {1,2,3,4,5}

and i wanted my function to only change the 3rd element i would have to pass the entire array plus another argument to the element i wanted it to change?

**laserlight** · 05-13-2019

No. Pass a pointer to the 3rd element.

**cooper1200** · 05-13-2019

ok im not getting this
i thought you just said you couldn't do that

**laserlight** · 05-13-2019

Where did I say you couldn't do that?

**cooper1200** · 05-13-2019

i think i get it now

Code:

int array[5] = {1,2,3,4,5}, int *p_array = array; // p_array points at element [0] ie 1
p_array + 2;// p_array now points at element [2] ie the 3
foo(p_array)

i re-read your first comment about xs[0] being wrong.... i keep confusing arrays becoming pointers and indexing pointers to arrays

**laserlight** · 05-13-2019

Aye, so foo(xs[0]) is wrong, but foo(&xs[0]) is correct and equivalent to foo(xs). For passing a pointer to the 3rd element, you could write foo(&array[2]), or more simply foo(array + 2).

**cooper1200** · 05-13-2019

while we are on the subject of pointers in general which is correct int* my array or int *myarray i did read a thread on here somewhere that argued the case for both

**laserlight** · 05-13-2019

Is ``int* p;'' right or is ``int *p;'' right?

**cooper1200** · 05-13-2019

thats the page i read. the reason i am learning c is to get a good grounding then i want to learn c++ (classes etc) then get into embedded systems and the like is learning int *array going to trip me up

**laserlight** · 05-13-2019

Nope, it's just subjective style.

**cooper1200** · 05-13-2019

i got it to compile with no warnings or errors but it still doesn't do what i want it to

Code:

void get_player_names(int num_of_players, Hand *p_player)
{
    int i, x, str_index = 0;
    char buff[2], str_temp[10];// *p_str_temp = str_temp;// *p_buff = buff;

    for (i = 0; i < num_of_players; i++)
    {
        printf("Please enter player %d's name: ", i + 1);
        x = 0;
        str_index = 0;
        while (x != 1)
        {
            fgets(buff, sizeof(buff), stdin);
            if (!strcmp(buff, "\n"))
            {
                strcpy(&str_temp[str_index], &buff[0]);
                str_index++;
            }
            else
            {
                strcpy(&str_temp[str_index], &buff[1]);// add the /0 onto the end of str_temp
                flush_line();//get rid of the "\n"
                x = sscanf(str_temp, "%s", p_player[i].player_name);
                if (x != 1)
                {
                    printf("Incorrect Entry\n Please enter player %d's name: ", i + 1);
                    x = 0;
                }
            }
        }
    }
    for (i = 0; i < num_of_players; i++)
    {
        printf("Player %d's name is %s\n", i, p_player[i].player_name);
    }
}

**cooper1200** · 05-13-2019

lets say the first players name is tom and the seconds is josie i want it to assign "tom" then move onto the next one without waiting for more input and therefore overwriting tom