Reading tab-separated values from text file into array

Question

Hey I am quite new to C++ and I am facing a problem:

I have a textfile which looks like this:

500

1120

10

number1,1 number1,2   ...   number1,500

number2,1

.

.

number1120,1

So the first two values on top of the text-file describe the dimensions of the matrix. I now want to write a code, which reads all the files from the matrix into an array or vector of int values. I can read the first three values (500, 1120,10) and write them into an integer value using getline and stringstream, but I can't figure out how to read the matrix tap separated with a loop.

Answer 1

You may consider to read the matrix line by line with a loop, and split the current line using a tokenizer (e.g. std::strtok) or a nested loop that splits the line at your delimiters. There is a thread about tokenizers.

Answer 2

Something like this:

#include <iostream>
#include <sstream>

// Assume input is 12,34,56. You can use 
// getline or something to read a line from
// input file. 
std::string input = "12,34,56";

// Now convert the input line which is string
//  to string stream. String stream is stream of 
// string just like cin and cout. 
std::istringstream ss(input);
std::string token;

// Now read from stream with "," as 
// delimiter and store text in token named variable.
while(std::getline(ss, token, ',')) {
    std::cout << token << '\n';
}