W3School TIY Editor

#include <iostream>

#include <map>

using namespace std;

​

int main() {

  map<string, int> people = { {"Bill", 19}, {"Steve", 32}, {"Elon", 26} };

​

  // 添加新元素

  people["Jack"] = 23;

  people["John"] = 25;

  people["Percy"] = 18;

  people["Alfred"] = 36;

​

  cout << "Jack 的年龄是: " << people.at("Jack") << "\n";

  cout << "Percy 的年龄是: " << people.at("Percy") << "\n";

  return 0;

}