What is NTUSER DAT file?

How do I fill arrays with numbers from a .dat file (in C++)?

• I have a two dimensional array that I need to fill with data from a .dat file. The .dat file contains its first segment as three columns of numbers and 522 rows. 522 is a global constant named M. The second segment has two columns and 891 rows. 891 is a global constant named N. The first two columns of the first segment are supposed to be in the 2D array called data[M][3] in the main function. The third column of the first segment of the .dat file is to be ignored. The first column of the second segment is supposed to be in a 1D array called color[N]. and the second column of the second segment is supposed to be in a 1D array called vertex[N]. M and N are unsigned ints. The problem is that when I cout the array values, the're all random (probably junk). Thanks for taking a look :-) Here's how my function is called in the main: int main() { double data[M][3]; unsigned int vertex[N]; int color[N]; read_dat(data, vertex, color); ....... Here's my function that's supposed to do it: void read_dat(double data[M][3], unsigned int vertex[N], int color[N]) { ifstream infile; unsigned int i, j, k, p, q; infile.open("shuttle.dat"); if(infile.fail()) { cout << "ERROR: input file opening failed." << endl; exit(1); } for(q = 0; q < M; q = q + 3) { infile.ignore(); // should get rid of the unnecessary third column } for(i = 1; i < M; ++i) { for(j = 0; j < 2; ++j) { infile >> data[i][j]; } } for(k = M + 1; k < M + N; ++k) { infile >> vertex[2*k]; // counts all even numbers (1st collumn) } for(p = M + 1; p < M + N; ++p) { infile >> color[2*p + 1]; // counts all odd numbers (2nd collumn) } }

• Answer:

  std::basic_istream::operator>>() and std::basic_ifstream::operator>>() on which your favorite classes are based will bounce once on the last item if you don't do this after reading your numbers or strings: infile >> data[i][j] >> std::ws; //be sure to eat whitespace after reading data so we can detect EOF! ifstream and cin both ignore whitespace BETWEEN data items (not including .getline()). use .good() to see if you have reached end of file or not or to see if something has failed. it's hard for me to tell without looking at your .dat file. I HOPE it has whitespace between the numbers. you should also .close() when you are finished with the file. when you do ignore(), exactly how much do you want to ignore? I think the default is 1 character. so you are probably going to have to munch some data and throw it away. this may be why you are getting garbage....