Thread: Help with using files with arrays

Hi!
I am trying to load the information in a file and put into an array. Can anyone tell me how I might do this? Also, how do start reading from a different line in a file? I am using fstream.h to do this. Thanks! ^_^

Thanks for the getline suggestion. My file will contain lines of numbers. I'm making a map file loading engine.

Someone please help!!!

I can help, I've done something like this before. Okay, let's say this the file (a 10x10 square):

1 = grass
2 = water
3 = mountain

2 2 2 2 2 2 2 2 2 2
2 2 1 1 1 1 3 1 2 2
2 1 1 1 3 3 1 3 1 2
2 2 1 3 1 1 3 1 1 2
2 2 2 1 1 1 3 1 2 2
2 2 1 1 3 2 2 1 1 2
2 1 1 3 3 2 1 3 2 2
2 2 2 1 3 1 3 1 1 2
2 2 2 2 2 1 1 2 2 2
2 2 2 2 2 2 2 2 2 2

This would require an array of 100 elements.

Code:

int islandMap[10][10];

To initialize this, let's say you have a function called InitMap().

Code:

void InitMap()
{
     ifstream map("island.map");
     char ch;
     for (int i=0; i<10; i++)
     {
          for (int j=0; j<10; j++)
          {
               map >> ch;
               islandMap[i][j] = (int *)ch;
          }
     }
}

Or something along those lines. I hope that helps a little. Let me know if that still won't work, I've another idea that may.

Brendan

Oops. In the above InitMap() function, where it says:

Code:

islandMap[i][j] = (int *)ch;

Take out the *. It will work then. So it should look like this:

Code:

islandMap[i][j] = (int)ch;

Brendan

Lol oops actually none of that will work. Here, this works, and I know this because I tested it:

Code:

void InitMap()
{
	char str[100];
	ifstream map("island.map");
	for(int i=0;i<=10;i++)
	{
		map>>str;
		for(int j=0;j<10;j++)
		{
			switch ((int)str[j])
			{
			case '1':
				islandMap[i][j]=1;
				break;
			case '2':
				islandMap[i][j]=2;
				break;
			case '3':
				islandMap[i][j]=3;
			}
		}
	}
}

A DispMap() function would look something like this:

Code:

void DispMap()
{
	for (int i=0; i<10; i++)
	{
		for (int j=0; j<10; j++)
		{
			switch (islandMap[i][j])
			{
			case 1:
				cout << "-";
				break;
			case 2:
				cout << "~";
				break;
			case 3:
				cout << "^";
				break;
			}
		}
		cout << "\n";
	}
}

Hope that helps!

Brendan