003_stl_std_unordered_map.cpp

#include <iostream>
#include <string>
#include <unordered_map>
 
int main()
{
    // 创建三个 string 的 unordered_map （映射到 string ）
    std::unordered_map<std::string, std::string> u = {
        {"RED","#FF0000"},
        {"GREEN","#00FF00"},
        {"BLUE","#0000FF"}
    };
 
    // 迭代并打印 unordered_map 的关键和值
    for( const auto& n : u ) {
        std::cout << "Key:[" << n.first << "] Value:[" << n.second << "]\n";
    }
 
    // 添加新入口到 unordered_map
    u["BLACK"] = "#000000";
    u["WHITE"] = "#FFFFFF";
 
    // 用关键输出值
    std::cout << "The HEX of color RED is:[" << u["RED"] << "]\n";
    std::cout << "The HEX of color BLACK is:[" << u["BLACK"] << "]\n";
 
    return 0;
}