College Study/C++ (ENG)23 [C++] C++ 11/14/17/... New STL (ENG) Unordered Map std::unordered_map std::unordered_multimap // std::map #include #include #include int main() { std::map scores; scores["Nana"] = 60; scores["Mocha"] = 70; scores["Coco"] = 100; for (auto it = scores.begin(); it != scores.end(); ++it) { std::cout first 2022. 1. 2. [C++] C++ 11/14/17/... New Types (ENG) nullptr The old C style of NULL is a number. // Class.h float GetScore(const char* name); // meant to call this float GetScore(int id); // actual // Main.cpp #define NULL 0 Class* myClass = new Class("COMP3100"); // ... int score = myClass->GetScore(NULL); So in C++ 11, you can use nullptr as a pointer. typedef decltype(nullptr) nullptr_t; // null pointer constant int number = NULL; // OK int* p.. 2022. 1. 2. [C++] C++ 11/14/17/... New Keywords (ENG) auto The keyword auto infers the data type automatically. It is not a dynamic type (like var of JavaScript). So you need to initialize auto's variables. auto x; // error auto x = "Chris"; // OK auto x = 50; // error It can get values, pointers, and even references (and so on). auto for pointers can omit *, but it's better to use * for readability of programmers. Reference types must use & so tha.. 2022. 1. 2. [C++] Template Programming (ENG) Function Template STL container is also a template. With template, you don't have to write codes in duplicate. template // typename can be replaced with class (even if it is not a class) T Add(T a, T b) { return a + b; } Function template is a template for functions. You can skip the template parameter. Add (3,10); Add (3,10); There's not the difference between typename and class, so I'll use ty.. 2022. 1. 2. [C++] Purpose of STL Container (ENG) the Purpose STL container has a standard interface that can be applied to every container. - It is a little weird. Extremely object-oriented. std::vector scores; scores.push_back(10); // seems like a stack std::list ages; ages.push_back(100); // seems like a stack std algorithms work in many containers. It is based on template programming. It allows the memory to be menaged automatically. - Freq.. 2022. 1. 2. [C++] Standard Template Library Container: Others (ENG) Set #include int main() { std::set scores; scores.insert(20); scores.insert(100); for (std::set::iterator it = scores.begin(); it != scores.end(); ++it) { std::cout 2022. 1. 2. [C++] Standard Template Library Container: Map (ENG) Creating Map A map stores pairs of key and value. Keys cannot be duplicated. C++ maps are automatically sorted. It is based on the binary search tree (ascending order). #include int main() { std::map simpleScoreMap; simpleScoreMap.insert(std::pair("Mocha", 100)); simpleScoreMap.insert(std::pair("Coco", 50)); simpleScoreMap["Mocha"] = 0; std::cout 2022. 1. 2. [C++] Standard Template Library Container: Vector (ENG) STL Container vector, map, set, stack, queue, list, deque ... STL container is a standard interface for all template-based containers. It allows for automatic memory management. Creating Vectors Vector is a dynamic array that can hold any data type. All elements in a vector are located in contiguous memory. Memory is automatically managed as the number of elements increase. You can randomly acce.. 2022. 1. 2. [C++] Exception (ENG) Out Of Range #include int main() { std::string myCatName = "Coco"; try { char ch = myCatName.at(5); } catch (const std::out_of_range& e) { std::cerr GetName(); std::cout 2022. 1. 2. 이전 1 2 3 다음
