Reading letters and numbers from .txt file - c++

Question

I program which reads the letters and numbers from the input being used. But i dont know how to implement this to a .txt file. This is my code:
#include <iostream>
#include <string>
using namespace std;
int main()
{
char ch;
int countLetters = 0, countDigits = 0;
cout << "Enter a line of text: ";
cin.get(ch);
while(ch != '\n'){
if(isalpha(ch))
countLetters++;
else if(isdigit(ch))
countDigits++;
ch = toupper(ch);
cout << ch;
//get next character
cin.get(ch);
}
cout << endl;
cout << "Letters = " << countLetters << " Digits = " << countDigits << endl;
return 0;
}
I made a mistake in my HW I was suppose to count the words instead of letters from the .txt file. Im having trouble counting words because I get confused with the space between words. How could I change this code to count the words instead of letters? I really appreciate the help.

Answer 1

This code counts each word separately. If the first character of a "word" is a number, it assumes the entire word is numeric.
#include <iterator>
#include <fstream>
#include <iostream>
int main() {
int countWords = 0, countDigits = 0;
ifstream file;
file.open ("your_text.txt");
string word;
while (file >> word) { // read the text file word-by-word
if (isdigit(word.at(0)) {
++countDigits;
}
else {
++countWords;
}
cout << word << " ";
}
cout << endl;
cout << "Letters = " << countLetters << " Digits = " << countDigits << endl;
return 0;
}

Answer 2

#include <iostream>
#include <fstream>
using namespace std;
int main()
{
char ch;
int countLetters = 0, countDigits = 0;
ifstream is("a.txt");
while (is.get(ch)){
if(isalpha(ch))
countLetters++;
else if(isdigit(ch))
countDigits++;
ch = toupper(ch);
cout << ch;
}
is.close();
cout << endl;
cout << "Letters = " << countLetters << " Digits = " << countDigits << endl;
return 0;
}