char arrray, how count the numbers of letters in a paragraph ?

[Alex A]

Hi guys,
the below program calculates the amount of capital and lower case letters on a paragraph saved in my flash drive. The program works fine ,but I would like to change the program so I dont use any global counters and instead just use an array. Can someone please point me the right direction ? Thanks to everyone in advance.

 
#include <iostream>
using namespace std;
#include <fstream>
#include <iomanip>
#include <ctype.h> 
void upper_case(char letter[]);
void writevalues();
int A = 0, B = 0, C = 0, D = 0, E = 0, F = 0, G = 0, H = 0, I = 0, J = 0, K = 0, L = 0, M = 0, N = 0, O = 0, P = 0, Q = 0, R = 0, S = 0, T = 0, U = 0, V = 0, W = 0, X = 0, Y = 0, Z = 0;
int a = 0, b = 0, c = 0, d = 0, e = 0, f = 0, g = 0, h = 0, i = 0, j = 0, k = 0, l = 0, m = 0, n = 0, o = 0, p = 0, q = 0, r = 0, s = 0, t = 0, u = 0, v = 0, w = 0, x = 0, y = 0, z = 0;
int main()
{
	char letter[1000];


	ifstream infile("I:\\TEXT DAT.txt");
	if (!infile)
	{
		std::cout << "Cannot open input file. Program terminates!\n";
		return 1;
	}

	do {
		infile >> letter;
		//call fucntion to calculate upper case letters
		upper_case(letter);
		//call function to write values to output file
		writevalues();


	} while (!infile.eof());

	return 0;
}


void upper_case(char letter[])
{

	for (int z = 0; letter[z] != '\0'; z++)
	{

		if (letter[z] == 'A')
		{

			A++;
		}
		else if (letter[z] == 'a')
		{
			a++;

		}
		else if (letter[z] == 'b')
		{
			b++;
		}
		else if (letter[z] == 'B')
		{
			B++;
		}

		else if (letter[z] == 'C')
		{
			C++;
		}
		else if (letter[z] == 'c')
		{
			c++;
		}

		else if (letter[z] == 'D')
		{
			D++;
		}
		else if (letter[z] == 'd')
		{
			d++;
		}

		else if (letter[z] == 'E')
		{
			E++;
		}
		else if (letter[z] == 'e')
		{
			e++;
		}

		else if (letter[z] == 'F')
		{
			F++;
		}
		else if (letter[z] == 'f')
		{
			f++;
		}

		else if (letter[z] == 'G')
		{
			G++;
		}
		else if (letter[z] == 'g')
		{
			g++;
		}

		else if (letter[z] == 'H')
		{
			H++;
		}
		else if (letter[z] == 'h')
		{
			h++;
		}

		else if (letter[z] == 'I')
		{
			I++;
		}
		else if (letter[z] == 'i')  
		{
			i++;
		}

		else if (letter[z] == 'J')
		{
			J++;
		}
		else if (letter[z] == 'j')
		{
			j++;
		}

		else if (letter[z] == 'K')
		{
			K++;
		}
		else if (letter[z] == 'k')
		{
			k++;
		}

		else if (letter[z] == 'L')
		{
			L++;
		}
		else if (letter[z] == 'l')
		{
			l++;
		}

		else if (letter[z] == 'M')
		{
			m++;
		}
		else if (letter[z] == 'm')
		{

			m++;
		}

		else if (letter[z] == 'N')
		{
			N++;
		}
		else if (letter[z] == 'n')
		{
			n++;
		}

		else if (letter[z] == 'O')
		{
			O++;
		}
		else if (letter[z] == 'o')
		{
			o++;
		}

		else if (letter[z] == 'P')
		{
			P++;
		}
		else if (letter[z] == 'p')
		{
			p++;
		}

		else if (letter[z] == 'Q')
		{
			Q++;
		}
		else if (letter[z] == 'q')
		{
			q++;
		}

		else if (letter[z] == 'R')
		{
			R++;
		}
		else if (letter[z] == 'r')
		{
			r++;
		}

		else if (letter[z] == 'S')
		{
			S++;
		}
		else if (letter[z] == 's')
		{
			s++;
		}

		else if (letter[z] == 'T')
		{
			T++;
		}
		else if (letter[z] == 't')
		{
			t++;
		}

		else if (letter[z] == 'U')
		{
			U++;
		}
		else if (letter[z] == 'u')
		{
			u++;
		}

		else if (letter[z] == 'V')
		{
			V++;
		}
		else if (letter[z] == 'v')
		{
			v++;
		}

		else if (letter[z] == 'W')
		{
			W++;
		}
		else if (letter[z] == 'w')
		{
			w++;
		}

		else if (letter[z] == 'X')
		{
			X++;
		}
		else if (letter[z] == 'x')
		{
			x++;
		}

		else if (letter[z] == 'Y')
		{
			Y++;
		}
		else if (letter[z] == 'y')
		{
			y++;
		}

		else if (letter[z] == 'Z')
		{
			Z++;
		}
		else if (letter[z] == 'z')
		{
			z++;
		}

	}

}

void writevalues()
{
	//Open lab7g_output.txt
	ofstream outfile("I:\\lab7g_output.txt");
	outfile << left;
	if (!outfile)
	{
		std::cout << "Cannot open input file. Program terminates!\n";

	}

	
	outfile << fixed << showpoint << setprecision(2);

	outfile << "A=" << a + A << endl;
	outfile << "B=" << B + b << endl;
	outfile << "C=" << C + c << endl;
	outfile << "D=" << D + d << endl;
	outfile << "E=" << E + e << endl;
	outfile << "F=" << F + f << endl;
	outfile << "G=" << G + g << endl;
	outfile << "H=" << H + h << endl;
	outfile << "I=" << I + i << endl;
	outfile << "J=" << J + j << endl;
	outfile << "k=" << K + k << endl;
	outfile << "L=" << L + l << endl;
	outfile << "M=" << M + m << endl;
	outfile << "N=" << N + n << endl;
	outfile << "O=" << O + o << endl;
	outfile << "P=" << P + p << endl;
	outfile << "Q=" << Q + q << endl;
	outfile << "R=" << R + r << endl;
	outfile << "S=" << S + s << endl;
	outfile << "T=" << T + t << endl;
	outfile << "U=" << U + u << endl;
	outfile << "V=" << V + v << endl;
	outfile << "W=" << W + w << endl;
	outfile << "X=" << X + x << endl;
	outfile << "Y=" << Y + y << endl;
	outfile << "Z=" << Z + z << endl;

}

[integralfx]

I'd recommend you have a function to read the data in your file, just to make main() cleaner. Also, you can convert all the characters in your file to uppercase/lowercase, using toupper() or tolower(), respectively. That way, you don't need to worry about case.

const int NUM_LETTERS{ 26 };    // global variable

// 'A'/'a' at index 0, 'B'/'b' at index 1, 'C'/'c' at index 2, etc...
int letter_count[NUM_LETTERS]{};    // in main()

string read_file( const string& filename )
{
    // read entire file into a string
}

void write_file( const string& filename, const string& data )

void count_letters( const string& data, int lttr_cnt[NUM_LETTERS] )
{
    for( char c : data ) {
        c = tolower( c );

        if( islower( c ) ) {
            // ASCII code of upper case letters
            // 'a' == 97 to 'z' == 122
            // e.g. if c == 'd'
            // 'd' - 'a' == 100 - 97
            //           == 3
            // which happens to be the index
            // of lttr_cnt which corresponds
            // to the count of 'd'
            lttr_cnt[ c - 'a' ]++;
        }
        else
            // punctuation, numbers, etc...
    }
}

[Alex A]

thanks ,

integralfx (591) is there any way to do this with no gloabal variables just by passing the array ?

[integralfx]

Yeah, that's possible as well.
void count_letters( const string& data, int lttr_cnt[], int num_lttrs )

[48T7M4Gy]

You can extend this by studying the ASCII table and apply filters and aggregation as you need:

#include <iostream>
#include <fstream>

int main ()
{
    char character;
    int array[255] = {0};
    
    std::ifstream myfile ("text_file.txt");
    if (myfile.is_open())
    {
        while ( myfile >> character )
        {
            array[character]++;
        }
        myfile.close();
        
        for(int i = 'a'; i <= 'z'; i++)
            std::cout << (char)i << ": " << array[i] << '\n';
        
        for(int i = 'A'; i <= 'Z'; i++)
                std::cout << (char)i << ": " << array[i] << '\n';
    }
    
    else std::cout << "Unable to open file";
    
    return 0;
}