erase in map stl code example

Example 1: map.erase in c++

it=mymap.find('b');
mymap.erase (it);                   // erasing by iterator
mymap.erase ('c');                  // erasing by key

Example 2: stl map remove item

it=mymap.find('b');
mymap.erase (it);                   // erasing by iterator

mymap.erase ('c');                  // erasing by key

it=mymap.find ('e');
mymap.erase ( it, mymap.end() );    // erasing by range