end |
C++ Library |
const_iterator end()const
Returns a const iterator which points just beyond the last object in the container. If the container is empty, the result is undefined.
iterator end()const
Returns a iterator which points just beyond the last object in the container. If the container is empty, the result is undefined.
#pragma warning(disable: 4786)
#include <map>
#include <iostream>
#include <string>
typedef std::map<int, std::string> MAP_INT_STR ;
typedef MAP_INT_STR::iterator MAP_ITERATOR ;
typedef MAP_INT_STR::reverse_iterator MAP_REVERSE_ITERATOR ;
typedef std::pair<int, std::string> PAIR_INT_STR ;
template <class ITERATOR>
void print_map_item(ITERATOR it)
{
std::cout << (*it).first << ", " <<
(*it).second << std::endl ;
}
int main()
{
//default constructor
MAP_INT_STR c1 ;
PAIR_INT_STR pairs[5] = { PAIR_INT_STR(1, std::string("one")),
PAIR_INT_STR(2, std::string("two")),
PAIR_INT_STR(3, std::string("three")),
PAIR_INT_STR(4, std::string("four")),
PAIR_INT_STR(5, std::string("five"))
};
//construct from a range
MAP_INT_STR c2(pairs, pairs + 5) ;
//copy constructor
MAP_INT_STR c3(c2) ;
//empty
if(c1.empty())
{
std::cout << "c1 is empty" << std::endl ;
}
else
{
std::cout << "c1 is not empty" << std::endl ;
}
//begin, end
std::cout << "c2 (using begin, end) = " << std::endl ;
MAP_ITERATOR Iter1 ;
for(Iter1 = c2.begin(); Iter1 != c2.end(); Iter1++)
{
print_map_item(Iter1) ;
}
//rbegin, rend
std::cout << "c2 (using rbegin, rend) = " << std::endl ;
MAP_REVERSE_ITERATOR RevIter1 ;
for(RevIter1 = c2.rbegin(); RevIter1 != c2.rend(); RevIter1++)
{
print_map_item(RevIter1) ;
}
//insert
std::pair<MAP_ITERATOR, bool> result ;
result = c1.insert(MAP_INT_STR::value_type(6, std::string("six"))) ;
if(result.second == true)
{
std::cout << "a pair of key/data was inserted in c1, *(result.first) = " ;
print_map_item(result.first);
}
else
{
std::cout << "pair(6, \"six\") was not inserted in c1" << std::endl ;
}
c1.insert(pairs, pairs + 5) ;
c1.insert(c1.begin(), PAIR_INT_STR(0, std::string("zero"))) ;
//find
std::cout << "Does c1 contain any pair with key = 6?" << std::endl ;
Iter1 = c1.find(6) ;
if(Iter1 != c1.end())
{
std::cout << "c1 contains pair:" ;
print_map_item(Iter1) ;
}
else
{
std::cout << "c1 does not contain any element with key = 6" << std::endl ;
}
//operator[]
c1[8] = "eight" ;
std::cout << "Last key/data pair in c1 = " ;
print_map_item(c1.rbegin()) ;
//max_size
std::cout << "max elements which c1 can hold uisng current allocator = "
<< c1.max_size() << std::endl ;
//size
std::cout << "number of elements in c1 = " << c1.size() << std::endl ;
//swap
c1.swap(c2) ;
std::cout << "Last key/data pair in c1 = " ;
print_map_item(c1.rbegin()) ;
//clear
c3.clear() ;
std::cout << "after calling c3.clear(), number of elements in c3 = "
<< c3.size() << std::endl ;
//get_allocator
MAP_INT_STR::allocator_type a1 = c3.get_allocator() ;
//key_comp
MAP_INT_STR::key_compare kc = c1.key_comp() ;
std::cout << "use function object kc to find less of (10, 4)..."
<< std::endl ;
if (kc(10, 4) == true)
std::cout << "kc(10, 4) == true, which means 10 < 4" << std::endl ;
else
std::cout << "kc(10, 4) == false, which means 10 > 4" << std::endl ;
//value_comp
MAP_INT_STR::value_compare vc = c1.value_comp() ;
std::cout << "use function object vc to compare int-string pairs..."
<< std::endl ;
std::cout << "pairs[0] = (" << pairs[0].first << ", "
<< pairs[0].second << ")" << std::endl ;
std::cout << "pairs[1] = (" << pairs[1].first << ", "
<< pairs[1].second << ")" << std::endl ;
if ( vc(pairs[0], pairs[1]) == true)
std::cout << "pairs[0] < pairs[1]" << std::endl ;
else
std::cout << "pairs[0] > pairs[1]" << std::endl ;
//upper_bound
Iter1 = c2.upper_bound(6) ;
std::cout << "first map element with key > 6 = " ;
print_map_item(Iter1) ;
//lower_bound
Iter1 = c2.lower_bound(6) ;
std::cout << "first map element with key 6 = " ;
print_map_item(Iter1) ;
//equal_range
std::pair<MAP_ITERATOR, MAP_ITERATOR> pair2 = c2.equal_range(6) ;
std::cout << "using c2.equal_range(6),first map element with key > 6 = " ;
print_map_item(pair2.second) ;
std::cout << "using c2.equal_range(6), first map element with key = 6 = " ;
print_map_item(pair2.first) ;
//count
std::cout << "does c2 contain an element with key 8 ?" << std::endl ;
if(c2.count(8) == 1)
{
std::cout << "c2 contains element with key 8" << std::endl ;
}
else
{
std::cout << "c2 does not contain element with key 8" << std::endl ;
}
//erase
c2.erase(c2.begin()) ;
std::cout << "first key/data pair of c2 is: " ;
print_map_item(c2.begin()) ;
c1.erase(c1.begin(), c1.end()) ;
std::cout << "after c1.erase(c1.begin(), c2.end()), number of elements in c1 = "
<< c1.size() << std::endl ;
if(c2.erase(8) == 1)
{
std::cout << "element with key 8 in c2 was erased" << std::endl ;
}
else
{
std::cout << "c2 does not contain any element with key 8" << std::endl ;
}
return 0 ;
}
c1 is empty c2 (using begin, end) = 1, one 2, two 3, three 4, four 5, five c2 (using rbegin, rend) = 5, five 4, four 3, three 2, two 1, one a pair of key/data was inserted in c1, *(result.first) = 6, six Does c1 contain any pair with key = 6? c1 contains pair:6, six Last key/data pair in c1 = 8, eight max elements which c1 can hold uisng current allocator = 268435455 number of elements in c1 = 8 Last key/data pair in c1 = 5, five after calling c3.clear(), number of elements in c3 = 0 use function object kc to find less of (10, 4)... kc(10, 4) == false, which means 10 > 4 use function object vc to compare int-string pairs... pairs[0] = (1, one) pairs[1] = (2, two) pairs[0] < pairs[1] first map element with key > 6 = 8, eight first map element with key 6 = 6, six using c2.equal_range(6),first map element with key > 6 = 8, eight using c2.equal_range(6), first map element with key = 6 = 6, six does c2 contain an element with key 8 ? c2 contains element with key 8 first key/data pair of c2 is: 1, one after c1.erase(c1.begin(), c2.end()), number of elements in c1 = 0 element with key 8 in c2 was erased