8 replies to this topic

[skastu01]

Hi - I need help in how to count the number of lowercase characters while reading input from a text file in C++.

Thanks.

[skastu01]

This is a portion of what I have attempted so far:

count=0;
indata >> a;

while ( !indata.eof() ) {
    indata >> a;
    cout<<a;
    count = count + 1;
       }

[artificial]

Read the text file and store its content in a char array. Then do this:

char cBuffer[256];

int nNumberOfLowercaseLetters = 0;


for(int a = 0; a < 256; a++)

{

   if(cBuffer[a] > 'Z')

      nNumberOfLowercaseLetters++;

}

The text file should consist of letters.

Greets,
artificial

[skastu01]

Great! What is cBuffer[256]? How would I store the contents in a character array?

[artificial]

skastu01 said:

Great! What is cBuffer[256]? How would I store the contents in a character array?

cBuffer is the char array that stores the text file's content.
Take a look at this: Link

Greets,
artificial

[d0s]

artificial said:

Read the text file and store its content in a char array. Then do this:

char cBuffer[256];

int nNumberOfLowercaseLetters = 0;


for(int a = 0; a < 256; a++)

{

   if(cBuffer[a] > 'Z')

      nNumberOfLowercaseLetters++;

}

The text file should consist of letters.

Greets,
artificial

I've never liked making assumptions over what does or does not exist in a text file. If using your paradigm above wouldn't:

char cBuffer[256];

int nNumberOfLowercaseLetters = 0;


for(int a = 0; a < 256; a++)

{

   if(cBuffer[a] >= 'a' && cBuffer[a] <= 'z' )

      nNumberOfLowercaseLetters++;

}

be a bit safer?

Normally though, i'd just use the islower() function out of ctype.h in the conditional.

[artificial]

d0s said:

I've never liked making assumptions over what does or does not exist in a text file.

You're right, but I wanted to show him the easiest solution. :)

Greets,
artificial

[skastu01]

Thank you for your assistance! I have successfully completed the program, and this is a"her".

[julmuri]

Blargh, wrote a sample before I read the thread trough.
So, heres how I might have done it. ( not tested )

#include <algorithm>

#include <iostream>
#include <fstream>

#include <string>

#include <cctype>


template < typename Char >
int lowerCount( const std::basic_string<Char>& str )
{
    int result = 0;

    std::for_each( str.begin(), str.end(), []( Char c )
    {
        result += std::islower( c );
    });

    return result;
}

int main( int argc, char* argv[] )
{
    std::fstream file( "some_file.txt" );
    int          fileSize = 0;
    std::string  fileContent;

    if ( !file.is_open() )
    {
        // failed to open file
        return 0;
    } // if

    file.seekg( 0, std::ios::end );
    fileSize = file.tellg();
    file.seekg( 0, std::ios::beg );

    fileContent.resize( fileSize );
    file.read( &fileContent[0], fileSize );
    file.close();

    std::cout << "lower count=" << lowerCount( fileContent ) << std::endl;

    return 0;
}