fstream reading file at C++ code example

Example 1: fstream in c++

#include<fstream>
int main()
{
  fstream file; 
  /*if we use fstream then we need to specify at least one 
  parameter mode like ios::out or ios::in else the file will not open */  
  file.open("filename.txt", ios::out|ios::in);
  /*all work with file*/
  file.close();
  return 0;
}

Example 2: file reading c++

int a, b;
    
ifstream bd; 
myfile.open("file.txt");

if (myfile.is_open())
	while (bd >> a >> b)
    	cout << a << b << endl;

else cout << "ERROR";