Get the size of map - C++ STL

C++ examples for STL:map

  1. HOME
  2. C++
  3. STL
  4. map

Description

Get the size of map

Demo Code

#include <iostream>
#include <string>
#include <map>
using namespace std;
void show(const char *msg, map<string, int> mp);
int main() {// w w  w  .  j  a  v a 2s  .c  o m
   // Declare an empty map that holds key/value pairs
   // in which the key is a string and the value is an int.
   map<string, int> m;
   // Insert characters into m. An iterator to the inserted
   // object is returned.
   m.insert(pair<string, int>("Alpha", 100));
   m.insert(pair<string, int>("Gamma", 300));
   m.insert(pair<string, int>("Beta", 200));
   // Declare an iterator to a map<string, itr>.
   map<string, int>::iterator itr;
   // Show the size of m, which is the number of elements
   // currently held by m.
   cout << "Size of m is " << m.size() << "\n\n";
   return 0;
}
// Display the contents of a map<string, int> by using
// an iterator.
void show(const char *msg, map<string, int> mp) {
   map<string, int>::iterator itr;
   cout << msg << endl;
   for(itr=mp.begin(); itr != mp.end(); ++itr)
      cout << "  " << itr->first << ", " << itr->second << endl;
   cout << endl;
}

Result


Related Tutorials