#include <iostream> #include <map> int main() {std::map<int,char> example = {{1,'a'},{2,'b'}}; for(int x: {2, 5}) { if(example.contains(x)) {std::cout<< x << ": Found\n"; } else {std::cout<< x << ": Not found\n"; } } } ...
std::map<Key,T,Compare,Allocator>::contains From cppreference.com <cpp |container |map boolcontains(constKey&key)const; (1)(since C++20) template<classK> boolcontains(constK&x)const; (2)(since C++20) 1)Checks if there is an element with key equivalent tokeyin the container. ...
#include <iostream>#include <unordered_map>intmain(){std::unordered_map<int,char>example{{1,'a'},{2,'b'}};for(intx:{2,5})if(example.contains(x))std::cout<<x<<": 找到\n";elsestd::cout<<x<<": 未找到\n";} 输出:
在赋值后可以使用 std::any_cast 将 std::any 所存储的值转换成特定类型，如果 std::any 中存储的...
HashMap 的 get/put/contains 函数 此用例展示了 HashMap 的基本使用方法。 代码如下: import std.collection.* main() { v……欲了解更多信息欢迎访问华为HarmonyOS开发者官网
std::map<int, int> m; }; int main() { //only std::vector<std::unique_ptr<int>> v -> ok std::vector<A> vecA; vecA.emplace_back(); //add a std::map -> fail std::vector<B> vecB; //vecB.emplace_back(); //add a std::map and...
#include <iostream> #include <map> int main() { std::map<int,char> example = {{1,'a'},{2,'b'}}; if (example.contains(2)) { std::cout << "Found\n"; } else { std::cout << "Not found\n"; } } 输出: Found参阅...
std::map<Key,T,Compare,Allocator>::swap std::map<Key,T,Compare,Allocator>::count std::map<Key,T,Compare,Allocator>::find std::map<Key,T,Compare,Allocator>::contains std::map<Key,T,Compare,Allocator>::equal_range std::map<Key,T,Compare,Allocator>::lower_bound std::map<Key,T,Compar...
Example Run this code #include <iostream>#include <unordered_map>intmain(){std::unordered_map<int,char>example{{1,'a'},{2,'b'}};for(intx:{2,5})if(example.contains(x))std::cout<<x<<": Found\n";elsestd::cout<<x<<": Not found\n";} ...
std::map<int, int> m; }; int main() { //only std::vector<std::unique_ptr<int>> v -> ok std::vector<A> vecA; vecA.emplace_back(); //add a std::map -> fail std::vector<B> vecB; //vecB.emplace_back(); //add a std::map and declare c...