Declare an iterator to a map<string, int> and get first element - C++ STL

Description

Declare an iterator to a map<string, int> and get first element

Demo Code

#include <iostream>
#include <string>
#include <map>
using namespace std;
void show(const char *msg, map<string, int> mp);
int main() {//from   w w  w.  j  a va2 s  .  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, int>.
   map<string, int>::iterator itr;
   // Display the first element in m.
   itr = m.begin();
   cout << "Here is the first key/value pair in m: "
   << itr->first << ", " << itr->second << endl;
   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

• Previous
• Next

Related Tutorials

• Add key value pair to map, and loop through element in map
• Demonstrate map used as associative array
• Declare map that holds key/value pairs in which the key is a string and the value is an int.
• Creates a map that works as a phone directory, in which a person's name is the key and the phone number is the value.
• Remove all pair from map using clear()