Philip Nicoletti
January 15th, 2004, 10:14 AM
First, I highly recomend not using "char*" variables
as keys in a map. What is being stored is actually
the address, the the string itself. This can cause a
lot of problems, the least being the elements
might not be sorted correctly. Use std::string instead
(or CString if you prefer). To get all the keys/values
you will need to use iterators, but you can use
the std::for_each algorithm so that you do not need
to write the loop with a loop iterator - just pass it
begin() and end(). See example below (notice that
I changed the order that you inserted the elements
and that the elements are not sorted correctly. Well,
probably not - it depends on how the compiler sets
up the char string constants).
#include <map>
#include <iostream>
#include <algorithm>
using namespace std;
struct PrintOut
{
void operator() (const pair<char* const,char> & thePair)
{
cout << thePair.first << " : " << thePair.second << endl;
}
};
int main()
{
char na[] = { 'a', 't', 's'};
map<char*, char> mapOfChar_Char;
mapOfChar_Char["third"] = na[2];
mapOfChar_Char["first"] = na[0];
mapOfChar_Char["second"] = na[1];
for_each(mapOfChar_Char.begin() , mapOfChar_Char.end() , PrintOut());
return 0;
}
Same code using std::string instead ...
#include <map>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;
struct PrintOut
{
void operator() (const pair<const string,char> & thePair)
{
cout << thePair.first << " : " << thePair.second << endl;
}
};
int main()
{
char na[] = { 'a', 't', 's'};
map<string, char> mapOfChar_Char;
mapOfChar_Char["third"] = na[2];
mapOfChar_Char["first"] = na[0];
mapOfChar_Char["second"] = na[1];
for_each(mapOfChar_Char.begin() , mapOfChar_Char.end() , PrintOut());
return 0;
}