| // base define
std::map <std::string, std::string> sColleagueMap;
// 插入元素
sColleagueMap.insert( std::pair<std::string, std::string>("rao", "haijun") );
sColleagueMap.insert( std::pair<std::string, std::string>("zhao", "jingjing") );
sColleagueMap.insert( std::pair<std::string, std::string>("fan", "junjie") );
// 访问指定元素
std::cout<<sColleagueMap.at("rao")<<std::endl;
// 判断map中是否包含某个元素
std::cout<<sColleagueMap.count("rao")<<std::endl;
// 查找map中是否包含某个元素
auto findIt = sColleagueMap.find("fan");
if(findIt != sColleagueMap.end() ){
std::cout<<"find the element:"<<findIt->first<<findIt->second<<std::endl;
}
// 遍历元素(不允许修改) 从前到后 C++11标准
auto sCollItConst = sColleagueMap.cbegin();
for(; sCollItConst!=sColleagueMap.cend(); ++sCollItConst){
std::cout<<sCollItConst->first<<sCollItConst->second<<std::endl;
}
// 遍历元素(不允许修改) 从后到前 C++11标准
auto sCollItConstr = sColleagueMap.crbegin();
for(; sCollItConstr!=sColleagueMap.crend(); ++sCollItConstr){
std::cout<<sCollItConstr->first<<sCollItConstr->second<<std::endl;
}
// 遍历元素(可以修改)从前到后
std::map<std::string, std::string>::iterator sCollIt = sColleagueMap.begin();
for(; sCollIt!=sColleagueMap.end(); ++sCollIt){
if(sCollIt->first == "rao"){
sCollIt->second = "yuke";
}
std::cout<<sCollIt->first<<sCollIt->second<<std::endl;
}
// 遍历元素(可以修改)从后到前
std::map<std::string, std::string>::reverse_iterator sCollItR = sColleagueMap.rbegin();
for(; sCollItR!=sColleagueMap.rend(); ++sCollItR){
if(sCollItR->first == "rao"){
sCollItR->second = "zhihao";
}
std::cout<<sCollItR->first<<sCollItR->second<<std::endl;
}
// 清空所有元素
sColleagueMap.clear();
std::cout<<sColleagueMap.size()<<std::endl;
// 判断map的所能hold到的最大element个数
std::cout<<"max:"<<sColleagueMap.max_size()<<std::endl;
char *pNew = new char[1024*1024*1024];
if(!pNew){
std::cout<<"malloc memory error!"<<std::endl;
}
std::cout<<"max:"<<sColleagueMap.max_size()<<std::endl;
delete[] pNew;
// 判断是否为空
std::cout<<sColleagueMap.empty()<<std::endl;
| 