Thread: Opening Text File

I am reading a text file which has two columns of data. The following program works when readfile.open(afile) is replaced simply with readfile.open("001.txt"). Why does it not work when I declare afile beforehand? Although it may not seem important for this particular code, it is necessary for my future tasks. Thank you in advance.

Code:

#include <iostream>
#include <fstream>
using namespace std;

int main (){
	string afile = "001.txt";
    	ifstream readfile;
    	readfile.open(afile);
	const int n = 10;
    	double x[n], y[n];
    	for (int i=0; i<n; i++)
	{
		readfile>>x[i]>>y[i];
		cout<<x[i]<<" "<<y[i]<<endl;
	}

	
	readfile.close();
}

Thanks a lot. Works perfectly.