c++ count amount of numbers in char array?

Question

I have a char array that has number 0-8 in it in char form

Board[0] = '0';
Board[1] = '1';
Board[2] = '2';
Board[3] = '3';
Board[4] = '4';
Board[5] = '5';
Board[6] = '6';
Board[7] = '7';
Board[8] = '8';

and some of them are changed to either an 'x' or an 'o' based on user input however I need to figure out a way so that I can tell the total number of them that aren't an 'x' or an 'o'.

What I mean is if say 4 of the 9 are either an 'x' or an 'o' I need to be able to get the fact that there are 5 left. I was attempting to use for each(char c in Board) and I got far enough to where I got it to list the chars that aren't an 'x' or an 'o' but I can't figure out how to get it to send how many are left to an int value. This is as far as I got.

    for each(char c in Board)
    {
        if (c != 'x' && c != 'o')
        {

        }
    }

Even if your compiler accepts that syntax, I wouldn't recommend submitting it. Your instructor expects you to use the syntax you've been taught this semester. Consult your textbook and class notes for the syntax of for loops. If you turn in this non-standard code, and your instructor isn't using the same compiler, then you'll probably get marked down because your instructor will be unable to test it. — Rob Kennedy
– Rob Kennedy, Commented Dec 10, 2012 at 20:20

Arne Mertz · Accepted Answer · 2012-12-10 22:26:09Z

2

You could try

auto n = std::count_if(Board, Board+9, std::isdigit);

edited Dec 10, 2012 at 22:26

answered Dec 10, 2012 at 20:12

Arne Mertz

24.7k4 gold badges56 silver badges91 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Sarfaraz Nawaz Over a year ago

It is not is_digit, it is isdigit.

Arne Mertz Over a year ago

@Astor there seem to be no '9' ;) corrected the misspelling, thanks.

Yakov Galka · Accepted Answer · 2012-12-10 20:12:15Z

1

You should define a counter that counts the number of these characters (by incrementing it):

int n = 0;
for (char c : Board)
{
    if (c != 'x' && c != 'o')
    {
        n++; // increment n by 1
    }
}

std::cout << n << '\n'; // use the result

answered Dec 10, 2012 at 20:12

Yakov Galka

72.9k16 gold badges149 silver badges226 bronze badges

1 Comment

Thomas Matthews Over a year ago

Another idea is to start with a variable counting the number of free spaces and decrement for every move.

juanchopanza · Accepted Answer · 2012-12-10 20:44:40Z

1

You can use a combination of std::isdigit and std::count_if

#include <cctype>    // for std::isdigit
#include <algorithm> // for std::count_if

int num = std::count_if(Board, Board+9, std::isdigit);

edited Dec 10, 2012 at 20:44

answered Dec 10, 2012 at 20:12

juanchopanza

228k35 gold badges421 silver badges493 bronze badges

Comments

cottonke · Accepted Answer · 2012-12-10 20:20:51Z

0

Assuming you don't just want any digit, and only those between 0 and 8 you could do this:

int count = 0;

for each(char c in Board)
{
    if (c >= '0' && c <= '8')
    {
        count++;
    }
}

cout << count << " are digits between 0 and 8 (inclusive)" << endl;

answered Dec 10, 2012 at 20:20

cottonke

1291 silver badge10 bronze badges

Collectives™ on Stack Overflow

c++ count amount of numbers in char array?

4 Answers 4

2 Comments

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

2 Comments

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related