Skip to main content

Sequence Containers: Vectors

Vectors are sequence containers representing arrays that can change in size.

Just like arrays, vectors use contiguous storage locations for their elements, which means that their elements can also be accessed using offsets on regular pointers to its elements, and just as efficiently as in arrays. But unlike arrays, their size can change dynamically, with their storage being handled automatically by the container.

Container properties

Sequence
Dynamic array
Allocator-aware



Example :


#include 
#include 

int main ()
{
  std::vector<int> myvector;
  for (int i=1; i<=5; i++) myvector.push_back(i);

  std::cout << "myvector contains:";
  for (std::vector<int>::iterator it = myvector.begin() ; it != myvector.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';

  return 0;
}

Labels:

Comments

Post a Comment

Popular posts from this blog

const used with functions

const used with functions : class Dog {    int age;    string name; public:    Dog() { age = 3; name = "dummy"; }         // const parameters and these are overloaded functions    void setAge(const int& a) { age = a; }    void setAge(int& a) { age = a; }         // Const return value    const string& getName() {return name;}         // const function and these are overloaded functions    void printDogName() const { cout << name << "const" << endl; }  // value of name can't be modified    void printDogName() { cout << getName() << " non-const" << endl; } }; int main() {    Dog d;    d.printDogName();        const Dog d2;    d2.printDogName();     }
Post a Comment
Read more

Structured Bindings

Returning multiple Values from function C++ 11 vs C++ 17 Returning compound objects Iterating over a compound collection Direct initialization Returning multiple Values from function C++ 11 vs C++ 17 :  C++ 11 (std::tie): std::tuple mytuple() {     char a = 'a';     int i = 123;     bool b = true;     return std::make_tuple(a, i, b);  // packing variable into tuple } To access return value using C++ 11, we would need something like: char a; int i; bool b; std::tie(a, i, b) = mytuple();  // unpacking tuple into variables Where the variables have to be defined before use and the types known in advance. C++ 17 : auto [a, i, b] = mytuple(); Returning compound objects :  This is the easy way to assign the individual parts of a compound type (such as a struct, pair etc) to different variables all in one go – and have the correct types automatically assigned. So let’s have a look at an ...
Post a Comment
Read more

POST 1 : std::thread in c++ | C++ 11

std::thread   C++  Thread support library std::thread. Threads enable programs to execute across several processor cores. Defined in header Class : thread Member types : native_handle_type Data Member  id    //represents the id of a thread (public member class) Member functions (constructor)    //constructs new thread object (public member function) (destructor)    //destructs the thread object, underlying thread must be joined or detached  (public member function) operator=    //moves the thread object  Observers  // Covered in NEXT POST Operations    // Covered in NEXT POST Constructor :   #include   void f1 ( int n ) { for ( int i = 0 ; i < 5 ; ++ i ) { std:: cout << "Thread 1 executing \n " ; ++ n ; std:: this_thread :: sleep_for ( std:: chrono :: milliseconds ( 10 ) ) ; ...
Post a Comment
Read more