Manipulating Character arrays in functions.

Hi guys,

Got a quick one this time.
Using a class Player (to store player name, etc) and having some trouble passing arrays as parameters.
In my definition of constructor, i have 2 arguments, first name and last name.
Now i have to use char arrays to store names.
In my Class Player, i have 2 private members, char arrays playerFirstName and playerLastName (both arrays hold 10 members).

eg:

private:

char playerFirstName[10];
char playerLastName[10];

why doesn't the below constructor work?

Code:

---


Player::Player(char firstName[], char lastName[])
{


  playerFirstName = firstName;
  playerLastName = lastName;



}

---

getting message: incompatible types in assignment of char* to char[10]...

So does it want a pointer to an array or something along those lines?

Regards,

-Kirill

You need strcpy to copy strings.

Better, use std::string for all strings.

Are you sure?

1. I'm supposed to use char array (for assignment).
2. I've done some quick testing, and the following works:

Code:

---


void displayArray(char toDisplay[])
{
   
    cout<< "Your array is: " << toDisplay << endl;
   
   
    }





int main()
{
   
   
    char name[10];
   
   
   
   
   
   
    cin>> name;
   
 
   
    displayArray(name);
    system("PAUSE");
   
   
}

---

but when i use the same thing in a class with constructor (in my first post) it won't...
confused..

Regards,

-Kirill

Pointers and arrays are very closely related in C/C++. If you have

Code:

---

char a[128];
char *b = a;

---

the value of a is the address of the first element of the array. If you want the fifth element of the array, both a[5] and b[5] work, they are synonymous. If you wanted to pass a to some function, you would pass it as a pointer rather than an array. The 128 element array 'a' is 128 bytes wide and cannot be easily passed to a function. The 8 (or 4) byte pointer a can be passed just like any other parameter.

Code:

---

Player::Player(char *firstName, char *lastName)
{


  strcpy(playerFirstName, firstName);
  strcpy(playerLastName, lastName);



}

---

That's what you want. Invoke the function in the same way that you were before (or use the string class as corned suggests)

Ah yes, just tried something else in my testing code,

so I can use the array (display it), but I can't copy from one array to another.

eg:

Code:

---


char currentArray[10]; //create new array of 10 characters.


void copyArray(char array[])
{

    currentArray = array; //will not work

}

---

So how do i copy from one array to another?

Regards,

-Kirill

Quote:

---

Originally Posted by kbro3

So how do i copy from one array to another?

---

See post #2 in this thread.

--
Mats

Quote:

---

Originally Posted by kbro3

Ah yes, just tried something else in my testing code,

so I can use the array (display it), but I can't copy from one array to another.

eg:

Code:

---


char currentArray[10]; //create new array of 10 characters.


void copyArray(char array[])
{

    currentArray = array; //will not work

}

---

So how do i copy from one array to another?

Regards,

-Kirill

---

strcpy for strings, memcpy for anything

Or std::string since this is C++
Then you can do an assignment, and be safe about it as well.

>> strcpy for strings, memcpy for anything
strcpy for C style strings, memcpy for any POD type. std::copy for anything copyable.

>> Or std::string since this is C++
I agree, but it sounds like the assignment requires character arrays.

It's also better to use cin.getline if you can, since cin >> is unsafe for character arrays.
The problem is that you can't copy an array by assigning it to somewhere else in C++.
Another problem is that when you try to use an array in such way, you get a pointer to the first element, so you'd only be re-assigning the address in memory where the data is located, hence getting two variables "falsely" containing the same data.

This might not make much sense to you (perhaps you don't understand what I just wrote), so remember to copy the string if this is your assignment. Pointers, if you haven't already learned them, comes later I'm guessing.

Quote:

---

since cin >> is unsafe for character arrays.

---

Use setw() to make it safe.

Code:

---

char buffer[SIZE + 1]; // Can hold SIZE characters plus the NUL.
cin >> setw(SIZE) >> buffer;

---

That's another way, I guess.