整数到整数文件读取

Question

I want to read file so that it should read integer by integer. I have read it line by line but i want to read it integer by integer.

This is my code:

void input_class::read_array()
{    
        infile.open ("time.txt");
        while(!infile.eof()) // To get you all the lines.
        {
            string lineString;
            getline(infile,lineString); // Saves the line in STRING
            inputFile+=lineString;
        }
        cout<<inputFile<<endl<<endl<<endl;
        cout<<inputFile[5];

        infile.close();
}

Answer 1

You should do this:

#include <vector>

std::vector<int> ints;
int num;
infile.open ("time.txt");
while( infile >> num)
{
    ints.push_back(num);
}

The loop will exit when it reaches EOF, or it attempts to read a non-integer. To know in details as to how the loop works, read my answer here , here and here .

Another way to do that is this:

#include <vector>
#include <iterator>

infile.open ("time.txt");
std::istream_iterator<int> begin(infile), end;
std::vector<int> ints(begin, end); //populate the vector with the input ints

Answer 2

You can read from fstream to int using operator>> :

int n;
infile >> n;