Vector & List in C++

Vector & List

Vector

Items are stored in contiguous memory and assigned their own slots. Each item in Vector can be accessed by index and new items can be inserted at the end or in the middle.

Vector automatically deletes [] to prevent memory leaks. 

Syntax for Vector

vector<type> variable_name (number of elements);

List

List can be inserted and deleted at every position.

If insertion and deletion are frequent, List is more advantageous than Vector.

One node in the list has its own value and the address of the next list. (Non-contiguous memory).

Syntax for List

list<type> variable_name;

Example code

int main() {
    vector<int> vec_arr = { 1,2,3 };
 
    for (auto &itr : vec_arr) //Auto type deduction in range-based for loop
        cout << itr << " "; // 1 2 3
    cout << endl;
 
    cout << vec_arr[1] << endl; // 2
    cout << vec_arr.at(1) << endl; // 2 
    cout << vec_arr.size() << endl; // 3
    
    vec_arr.resize(5);
    vec_arr.push_back(3);
 
    for (auto &itr : vec_arr) 
        cout << itr << " "; // 1 2 3 0 0 3
    cout << endl;
 
    list<int> list;
    list.push_back(5);
    list.push_front(3);
 
    for (auto &itr2 : list)
        cout << itr2 << " "; // 3 5
    cout << endl;
 
    return 0;
}