File handling, character check

Im trying to write a program that can check text files for certain characters,like numbers , letters ect, what am I doing wrong here.

Code:

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

int main()
{

    ifstream one;

    one.open("test.txt");
//character
    char c;

    while (one.good())
    {
    c=one.get();//get character

        //see if its equal to what we want
        if(c=="f")
        {
        cout<<"yes its here";
        }


    }
return 0;
}

when I try to check for a letter I get an error saying it cant allow a comparison between pointer and integer.

When I try to search for a number it works, as in it loads, but dosent seem to see the number in my file.

you have to use single quotes. those double quotes create am array or characters that is null terminated

Use this

Code:

if (c =='f'){
    bla bla
}

Im having problems reading 2 or more digit numbers,like 30 and 43 , I think get is turning my charecters into asci codes thats why Im able to count spaces and commas and single digit numbers between 0 and 9.

What I want to do is count how many times numbers within a certain range appear in my file, what should I do?

Code:

int main()
{
int i=0,l=0,k=0;
int j[65]={0};
    ifstream one;
    

    one.open("test.txt");
    //character
    int c;

    while (one.good())
    {
    c=one.get();//get character

        for(i=0;i<65;i++)
        {
            if(c==i)
            {
            j[i]++;
            }
        }
    }
return 0;
}