mapped_type -> _Tp -> int hasher - > _Hash = hash<_Key> -> hash<std::string> key_equal -> _Pred = equal_to<_Key> -> equal_to<std::string> _Alloc = allocator<pair<const _Key, _Tp> > > -> allocator<pair<const std::string, int> > unorderd_map内部持有__hash_table对象,...
int main() { //创建一个unordered_map,键为string类型,值为int类型 std::unordered_map<std::string, int> map; //向map中插入键值对 map["apple"] = 1; map["banana"] = 2; map["orange"] = 3; //输出map中的键值对 for (const auto& pair : map) { std::cout << pair.first << "...
std::map<int,std::string> map1; map1.insert(std::pair<int,std::string>(1,"abc"));//pair定义在 <utility>map1.insert(std::map<int,std::string>::value_type(2,"bbb"));//不会覆盖前面的(2,bcd),等于插入失败map1.insert(std::make_pair(6,"sss")); map1[0] ="ddd";//这种方...
unordered_map<string, int>stu_score; unordered_map<string, int> score2 = {{"Lily", 92}, {"Tom", 91}}; pair<string, int> stu1("Lucy", 88); stu_score.insert(stu1); // copy insertion stu_score.insert(make_pair<string, int>("Jim", 96)); // move insertion stu_score.insert...
map>#include<string>intmain(intargc,char*argv[]){std::unordered_map<int,std::string>test_map...
std::unordered_map<std::string, int> myMap; ``` 2.插入键值对: ```cpp myMap["apple"] = 1; myMap["banana"] = 2; myMap["orange"] = 3; ``` 3.访问键对应的值: ```cpp int appleValue = myMap["apple"]; // appleValue = 1 ``` 4.检查键是否存在: ```cpp bool hasAppleKe...
int main() { std::unordered_map<std::string, int> myMap; myMap["apple"] = 1; myMap["banana"] = 2; myMap["cherry"] = 3; 3. 使用迭代器遍历 unordered_map 并打印键值对 使用迭代器遍历 unordered_map 是一种常见的方法: cpp // 使用迭代器遍历 for (auto it = myMap.begin...
int main() { // 定义一个map对象 map<int, string> m; // 用insert函数插入value_type数据 m.insert(map<int, string>::value_type(222, "pp")); // 用数组方式插入 m[123] = "dd"; m[456] = "ff"; std::map<char, int> mymap; // 插入单个值 mymap.insert(std::pair<char, int>...
std::unordered_map<int, std::string> map_name; map_name.insert({1, "apple"}); map_name.insert({2, "banana"}); ``` 除了上面的示例之外,我们还可以使用emplace()函数、operator[]、或者用C++11引入的列表初始化方式来向unordered_map中添加元素。例如: ```C++ map_name.emplace(3, "orange")...
unordered_map<string,int> months; //插入数据 cout<<"insert data"<<endl; months["january"]=31; months["february"] = 28; months["march"] = 31; months["september"] = 30; //直接使用key值访问键值对,如果没有访问到,返回0 cout<<"september->"<<months["september"]<<endl; ...