stl - w3toppers.com

Sorting a vector of custom objects

A simple example using std::sort struct MyStruct { int key; std::string stringValue; MyStruct(int k, const std::string& s) : key(k), stringValue(s) {} }; struct less_than_key { inline bool operator() (const MyStruct& struct1, const MyStruct& struct2) { return (struct1.key < struct2.key); } }; std::vector < MyStruct > vec; vec.push_back(MyStruct(4, “test”)); vec.push_back(MyStruct(3, “a”)); vec.push_back(MyStruct(2, “is”)); vec.push_back(MyStruct(1, “this”)); std::sort(vec.begin(), … Read more

Is the code valid. If i want to display first element? if not then what will s.begin() return?

In C++, the begin() member function returns a pointer (or iterator) to the front (a lot of the time, anyways). You can access the first element with begin(), but you have to dereference it (like a pointer) first: cout << *s.begin(); // 5 Here is a demo: https://repl.it/JQiU/0

stl::map assert [closed]

The following method definition ListofName GetList(){ &m_List;} is simply wrong ! Replace it with ListofName& GetList(){ return m_List;} And use it as a reference to an object and not a pointer to an object, meaning use “.” instead of “->” for( ListofName:: iterator itrList = GetList().begin(); itrList != GetList().end(); itrList++) I suggest you read a … Read more