Thread: Char Array Initialization and Display

First off, thank you for your earlier tips, I learned alot and one of those things is to approach my code a step at a time.The following is something I am not clear about. Multi dimensional char arrays and the displaying of them.

Code:

#include <iostream>


using namespace std;


main()
{


  //char test[5][5] = {'***\0','***\0','***\0','***\0','***\0'};
    char test[5][5] = {"***\0","***\0","***\0","***\0","***\0"};
	cout << test << endl;
	cout << char[2][2] << endl;


	cin.get();
	return 0;


}

The commented out expression didn't run at all but the double quotation mark one did, unfortunately, it gives me a hexadecimal display. How can I get it to display like this:

*****
*****
*****
*****
*****

The first failed because you're trying to initialize a 2d array of chars by stuffing more than a single character into an index position.

Code:

char test[5][5] = 
{
    { '*', '*', '*', '*', '\0' },
    { ... },
    { ... },
    { ... },
    { ... }
};

The second is being treated as 5 strings capable of holding up to 4 characters + 0 to terminate them... sort of.

cout test[2][2], wants to print a single character; the 3rd character of the 3rd string. to print the lines, use a loop

Code:

for(int i=0; i < 5; ++i)
    cout << test[i] << "\n";

To print the lines as you'd like, your declaration should be

Code:

char test[5][6] = {  "*****", "*****", "*****", "*****", "*****" };

loop

Using the string class is probably a good idea.

Awesome! I ran through the suggestions and modified my code and it works like a charm but when continuing on and adding to my code, I added a loop to write to a .txt file and it won't work. Here is my code. No erors, just doesnt write. TXT file was pre created prior to compiling.

Code:

#include <iostream>
#include <fstream>


using namespace std;


main()
{
	ofstream outputFile;
	outputFile.open("grid.txt");
	
    char test[5][5];
	
	for(int i = 0; i < 5; i++) 
	{
		for(int j = 0; j < 5; j++) 
		{
        test[i][j] = '*';
		}
	}
	
	for(int b = 0; b < 5; ++b && cout << endl)
	{
		for(int a=0; a < 5; ++a)
		outputFile << test[b][a];
	}
	
	for(int b = 0; b < 5; ++b && cout << endl)
	{
		for(int a=0; a < 5; ++a)
		cout << test[b][a];
	}
	
	
	
	outputFile.close();


	cin.get();
	return 0;


}

you should check that your file is open before you try and read/write to it.

Code:

if(outputFile.is_open())
{ 
     ...
}

I don't use cpp often, but I got an output file using

Code:

int i, j;
...

if(outputFile.is_open())
{
    for(i=0; i < 5; ++i)
    {
         for(j=0; j < 5; ++j)
         {
              test[i][j] = '*';
              cout << test[i][j];
              outputFile << test[i][j];
         }
         cout.flush() << "\n";
         outputFile.flush() << "\n";
    }

    outputFile.close();
}
...