Thread: Creating a multi-dimension array with file input

char buffer[BUFF_SIZE];
fgets( buffer, sizeof(buffer), input);

Have you read a FAQ?

I got the fgets part to copy the first string into a buff array but i am not exactly sure how to use the sscanf function.

This is what I have, but I need to get it to store it to the arrays days.
This results in a runtime error.

Code:

int main()
{
	//arrays for the first two lines of input file
	char location[25], month_year[25];
	//array for each day of the month
	int days[40][8], status = 0, n = 0; 
	char buff[8];

	FILE *input, *output;
	input = fopen("input.txt", "r");
	output = fopen("output.xt", "a");
    
	//fills in the arrays for the location and year
	fgets(location, 25, input);
	fgets(month_year, 25, input);

	//fills in the array for the days of the month
	fgets(buff, 8, input);
	sscanf(buff, "%d %d", days[n][8]);

	return 0;
}

http://faq.cprogramming.com/cgi-bin/...&id=1043284392

You are including <stdio.h>, right?

Code:

sscanf(buff, "%d %d", days[n][8]);

You are passing only one too few parameters, and the last parameter should have an & before it. And the whole thing should perhaps be in a for loop.

To write to the output file you can use fputs() or fprintf().

Well I cant get it to go with a multi-dimension array and I think that it may be easier 2 seperate arrays (maybe...). Anyways here is what I am trying and I am still getting this error:
Homework 7 (problem 1) error C2440: '=' : cannot convert from 'char *' to 'int'

Code:

int main()
{
	//arrays for the first two lines of input file
	char location[25], month_year[25], temp[8];
	//array for each day of the month
	int n = 0, status, array_number = 0; 
	float days[45], rain[45];

	FILE *input, *output;
	input = fopen("input.txt", "r");
	output = fopen("output.xt", "a");
    
	//fills in the arrays for the location and year
	fgets(location, 25, input);
	fgets(month_year, 25, input);

	//fills in the array for the days of the month
	for (status = fgets(temp, 8, input);
		status != EOF;
		status++)
	{
		int n = 0;
		while (temp[n] != '\n')
			n++;
		sscanf(temp, "%f %f", &days[array_number], &rain[array_number]);
		array_number++;
	}

	return 0;
}

And if I where to try the multi-dimensions (which may be easier to pass this to different functions) here is the code that I am trying for that part of it (I run into a runtime erroe when it gets to the sscanf part):

Code:

int main()
{
	//arrays for the first two lines of input file
	char location[25], month_year[25];
	//array for each day of the month
	int status, n = 0, array_number = 0; 
	char days[40][8], temp[8];

	FILE *input, *output;
	input = fopen("input.txt", "r");
	output = fopen("output.xt", "a");
    
	//fills in the arrays for the location and year
	fgets(location, 25, input);
	fgets(month_year, 25, input);

	//fills in the array for the days of the month
	for (status = 0;
		 status != EOF;
		 status++)
	{
		fgets(temp, 8, input);
		int n = 0;
		while (temp[n] != '\n')
			n++;
		sscanf(temp, "%f %f", &days[array_number][40]);
		array_number++;

	}

	return 0;
}

while (temp[n] != '\n')
n++;

You do nothing here
read the FAQ how to remove '\n' character from the buffer

sscanf(temp, "%f %f", &days[array_number][40]);

you ask to read 2 tokens, but provide only one variable
you ask to read 2 float values, but provide pointer to the char*

Your first value is a day (int from the 0 to 31)
Your second value is a double

Maybe you should think about using a struct for storing this pair of values

I am still having trouble with this. I dont understand the errors that I am getting. I would like to try to make a for loop so that I can scan the file in until the end of the file, but I get errors when trying to build the solution. Here are the two errors that i receive when trying to build:

error C2440: '=' : cannot convert from 'char *' to 'int'
error C2440: '=' : cannot convert from 'char *' to 'int'


I can't figure out how to get rid of these

Also I am not familiar with "struct". I dont know what these are.

Code:

int main()
{
	//arrays for the first two lines of input file
	char location[25], month_year[25];
	//array for each day of the month
	int status, n = 0, array_number = 0, days[45] = {0}; 
	char buff[8];
	double rain[45] = {0};

	FILE *input, *output;
	input = fopen("input.txt", "r");
	output = fopen("output.xt", "a");

	//fills in the arrays for the location and year
	fgets(location, 25, input);
	fgets(month_year, 25, input);

	//fills in the array for the days of the month
	for (status = fgets(buff, 8, input);
		 status != EOF;
		 status = fgets(buff, 8, input))
	{
		int n = 0;
		while (buff[n] != NULL)
			n++;
		sscanf(buff, "%d %.2lf", &days[array_number], &rain[array_number]);
		array_number++;
	}

	return 0;
}

http://msdn.microsoft.com/library/de...2c_.fgetws.asp

fgets returns char* not int

because fgets returns char* and EOF is int
have you read the reference for the fgets?

So would a while loop be eligable in this situation?