insert

插入一个元素

size

获得map中元素的个数

max_size

获得map所能容纳的元素个数

count

判断是否存在某个key，存在为返回1

find

查找某个key

erase

删除指定的元素

clear

清空map

empty

判断map是否为空

begin

获取map的第一个元素，一般遍历的时候用

end

获取map的最后一个元素，一般遍历的时候用

rbegin

获取map的第一个元素，一般倒序遍历时候用

rend

获取map的最后一个元素，一般倒序遍历时候用

value_comp

Retrieves a copy of the comparison object that is used to order element values in a map.

lower_bound

Returns an iterator to the first element in a map that has a key value that is equal to or greater than that of a specified key.

upper_bound

Returns an iterator to the first element in a map that has a key value that is greater than that of a specified key.

swap

Exchanges the elements of two maps.

equal_range

Returns a pair of iterators. The first iterator in the pair points to the first element in a map with a key that is greater than a specified key. The second iterator in the pair points to the first element in the map with a key that is equal to or greater than the key.

get_allocator

Returns a copy of the allocator object that is used to construct the map.

key_comp

Returns a copy of the comparison object that used to order keys in a 

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// 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;