need a clue

hi everybody...
i want to test to see if an input string
is part of an array of srtings
for example
if I declare a string of 8 months:

Code:

const char *months[8] = {"January", "February", "March", "April", "May", "June", "July", "August"};

how do i test if a cin'd month name is part of that set
(so i can have a trap if invalid data is entered)
I have tried many combination of string compare and am not having any luck
thanks
surfer grrl

A simple for-loop to loop through the months and then compare it to the input:

Code:

const int NrOfMonths = 12;
const char* Month[] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};

bool CheckMonth(char* MonthToCheckWith)
{
   for(int i=0; i<NrOfMonths; i++)
   {
      if(strcmp(Month[i], MonthToCheckWith) == 0) return true;
   }
   return false;
}

sorry i have tried EVERY imaginable combo of that am am still getting;

Code:

C:\Program Files\Microsoft Visual Studio\MyProjects_M\Sem_2\4_1\4_1.cpp(125) : error C2664: 'strcmp' : cannot convert parameter 1 from 'char' to 'const char *'

here is the entire program ...if you can:PLEASE help!!

Code:

# include <iomanip>
#include <string>
# include <fstream>
# include <iostream>
using namespace std; 

class Month{
public:
 void Month::Load(Month[]);
 int Month::calcdays(const Month[], int);
 int Month::calcdays(const Month[], char*);
 void Month:: printResult(const Month[],int, int); 


 int MonthNumber;
 char MonthName[10];
 char MonthAbrv[5];
 int MonthDays;
 }; 

char month[12][10] = { "January", "February", "March", "April", "May", "June", "July", "August"};
const MAXMONTHS = 12; 

//extern file with Month load data
ifstream infile("C:\\CODE\\INF\\3abc\\IF3abc.TXT"); 

int main ()
{ 

Month AM[MAXMONTHS];
int nm = 0;
int total = 0;
char month[10]; 

if (!infile) 
{
cerr << "Cannot open input file" << endl;
}//if
 else 
 { 

 AM[MAXMONTHS].Load(AM); 

  cout << "\n\n" << setw(55) << "Year-To-Date Number of Days Calculation" << endl; 

 for (int i = 0; i< MAXMONTHS; i++)
 {
  cout << "\n\n" << setw(55) << "Enter Number of Month (i.e. Dec = 12): ";
  cin >> nm;
  
  total = AM[MAXMONTHS].calcdays(AM, nm);
  if (total ==0)
  {}//don't print result if entry is invalid
  else
  {AM[MAXMONTHS].printResult(AM,nm, total);}
  
  
  cout << "\n\n" << setw(61) << "Enter Name of Month (capitalize 1st letter): ";
  cin >> month;
 
  total = AM[MAXMONTHS].calcdays(AM, month);
 

  AM[MAXMONTHS].printResult(AM, nm, total);
  

 }//for 

}//else 

return 0; 

}//main 

  

//data load-----------------------------
void Month::Load(Month AM[])
//in:AM; out:none
{ 
 for (int n = 0; n < 12; n++) {
 infile >> AM[n].MonthNumber;
 infile >>(AM[n].MonthName); 
 infile >>(AM[n].MonthAbrv);
 infile >>(AM[n].MonthDays); 

 }//for 
}//fx load 


//calculate days 1-----------------------
int Month::calcdays(const Month AM[], int nm)
//in:AM, nm; out:none
{
 int total=0;
 int n = 0;
if (nm < 1 || nm > 12) 
  {
   cout << "\n\n" << setw(33) << "<<Invalid Entry>>";
   return 0;
   
  }//if
  else
  {
   while (AM[n].MonthNumber <= nm) 
   {
   total += AM[n++].MonthDays;
   }//while 

   return total;
  }//else 

}//fx calcdays 1 

//calculate days 2--------------------------
int Month::calcdays(const Month AM[], char *month)
//in:AM, month; out:none
{


int total=0; 
for (int i =0; i < MAXMONTHS; i++)
{
	
    if ( strcmp(month[i], *month) == 0 ) 
	{
		cout << "\n\n" << setw(33) << "<<Invalid Entry>>";
	return 0;
	}

 for (int n = 0; n < 12; n++) 
 {
 total += AM[n].MonthDays;
 if ( strcmp(month,AM[n].MonthName ) == 0)
 break;
 }//for


 return total; 
}
}//fx calcdays 2 

  

void Month:: printResult(const Month AM[], int nm, int total) 
//in:AM, nm; out:none
{ 

   cout << "\n\n" << setw(63) << "The total days in the year up to and including "
  <<AM[nm-1].MonthName<< " = " 
  <<total<<endl; 

}//fx PrintResult

>>if (strcmp(month[i], *month) == 0)
What exactly are you trying to do on this line?

see if the input month is one of the valid months of the yr - if not return 0 or say "entry is invalid"

Your code

Code:

if (strcmp(month[i], *month) == 0)

Magos code

Code:

if(strcmp(Month[i], MonthToCheckWith) == 0)

Don't dereferense the month's name. Doing so will get you the first character, and won't be a valid input to the strcmp function.
Only pass the pointer...

Any ideas on why JANUARY is not found in the program below? If you add some other string as the first element in the set, JANUARY is found, but the new string is not.

Code:

#pragma warning(disable:4786)

#include <set>
#include <iostream>
using namespace std;

template <typename T>
class mycomp {
	public:
    bool operator()(T s1, T s2) const
    {
			return strcmp(s1, s2) == 0; 
}
};


int main()
{
	typedef set<const char*, mycomp<const char*> > MonthSet;
	
	MonthSet months;

	// months.insert("HUH?!");
	months.insert("JANUARY");
	months.insert("FEBRUARY");
	months.insert("MARCH");
	months.insert("APRIL");
	months.insert("MAY");
	months.insert("JUNE");
	months.insert("JULY");
	months.insert("AUGUST");
	months.insert("SEPTEMBER");
	months.insert("OCTOBER");
	months.insert("NOVEMBER");
	months.insert("DECEMBER");

	char input[64];
	
	cout<<"Enter month: ";
	cin>>input;

	MonthSet::iterator i = months.find(input);
	if ( i != months.end() ) {
		cout<<endl<<"Found!"<<endl;
	}

	return 0;
}

The iterator starts at 1 instead of 0 ?
I've never used iterators myself, I prefer good ol' loops where you know what is happening .

I reject the idea that something isn't good because you don't understand it. And I agree with the STL concept that explicit loops should be avoided in favor of algorithms when possible.

And the documentation seems to indicate that it will start searching from the beginning of the sequence, until a match is found:

set::find
const_iterator find(const Key& key) const;
The member function returns an iterator that designates the earliest element in the controlled sequence whose sort key equals key. If no such element exists, the iterator equals end().


I personally think this is a bug in Visual C++ 6. But I was wondering if anyone else knows for sure that the example is incorrect, or if someone can verify that the example works, with say, g++ or something. Thanks.

I'm a blockhead. The comparison function was wrong. Supposed to be a less-than function.

Code:

template <typename T>
class mycomp {
	public:
	bool operator()(T s1, T s2) const
	{
	        return strcmp(s1, s2) < 0; 
	}
};