c++ arrays and pointers

[Kabamaru]

so how can i get the frequency of an element in an array using pointers?

[jsmith]

I assume you want to count how many times a particular value occurs in an array?

Walk the array start to finish and keep a counter of the number of occurrences...

[kempofighter]

http://cplusplus.com/reference/algorithm/count_if/
http://cplusplus.com/reference/algorithm/count/

Both work nicely for arrays or template containers.

[Kabamaru]

xxx

[Medea]

xxx

[boubounas]

fgh

[Medea]

boubounas, i think like this if the variable letter is i.e. "a" it doesnt count if there is an "A" in the string

[boubounas]

xxx

[Medea]

yorgo??? NEXT QUESTION PLEASE

[jsmith]

It is still possible to do this with count_if (in one line of code, no less), however as this is for a homework assignment, I doubt it will be acceptable that way. Nonetheless, in the name of education, I give an "advanced" solution:

#include <algorithm>
#include <ctype>     
#include <string.h>  
#include <boost/bind.hpp>

int letterfrequency( char s[], char letter ) {
    return std::count_if( s, s + strlen( s ),
        boost::bind( tolower, _1 ) == boost::bind( tolower, letter ) );
}

Or very slightly better performance, but 2 lines

#include <algorithm>
#include <ctype>     
#include <string.h>  
#include <boost/bind.hpp>

int letterfrequency( char s[], char letter ) {
    int as_lower_case = tolower( letter );
    return std::count_if( s, s + strlen( s ),
        boost::bind( tolower, _1 ) == as_lower_case );
}