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Containers are data structures that manage collection of objects.

Array : Array is a data type that stores multiple elements of same data type. We have discussed details about arrays in previous section.
Vectors : These are dynamic arrays that can grow and shrink their size. Elements in vectors can be accessed using indexing.

vector.cpp

#include <iostream>
#include <vector>  //header file for vector
using namespace std;
int main(){
	//declaration of vector
	//vector <datatype> nameOfVector;
	vector <int> v;
	
	v.push_back(1);
	cout<<"Element in v is "<<v[0]<<endl;
	//pushing some more elements
	v.push_back(2);
	v.push_back(3);
	v.push_back(4);
	//printing all elements of vector
	for(int i=0; i<v.size(); i++){
		cout<<"Element "<<i+1<<" is "<<v[i]<<endl;
	}
	
	
	v.pop_back();
	cout<<"After poping last element :\n";
	for(int i=0; i<v.size(); i++){
		cout<<"Element "<<i+1<<" is "<<v[i]<<endl;
	}
	
}

Methods	Description
push_back()	It is used to push elements to a vector
pop_back()	It is used to pop elements from a vector
capacity()	It is used to check how many elements can be inserted to a vector.
size()	It is used to check how many elements are there in a vector
front()	It gives the reference to the first element in a vector
back()	It gives the reference to the last element in a vector
swap()	It exchanges the elements between vector
empty()	It checks if the vector is empty or not
clear()	It removes all the elements from the vector.
resize()	It modifies the size of the vector.

Deque is a short from of Double Ended Queue. It allows the insertion and deletion of elements from both ends.

deque.cpp

#include <iostream>
#include <deque>  //header file for deque
using namespace std;
int main(){
	//declaration of deque
	//deque <datatype> nameOfDeque;
	deque <int> d;
	
	d.push_back(1);
	cout<<"Element in v is "<<d[0]<<endl;
	d.push_front(33);
	d.push_back(2);
	d.push_back(3);
	d.push_back(4);

	//printing all elements of deque
	for(int i=0; i<d.size(); i++){
		cout<<"Element "<<i+1<<" is "<<d[i]<<endl;
	}
	
	
	//removing elements at the end of deque
	d.pop_back();
	d.pop_front();
	cout<<"After poping last element :\n";
	for(int i=0; i<d.size(); i++){
		cout<<"Element "<<i+1<<" is "<<d[i]<<endl;
	}
	
}

List is a linear data structure that stores elements in a sequence, and each element (node) in the list contains a value and two pointers: one to the previous element and one to the next element.

list.cpp

#include <iostream>
#include <list>
using namespace std;

int main() {
    std::list<int> myList;

    // Inserting at the back of the list
    myList.push_back(10);
    myList.push_back(20);
    myList.push_back(30);

    // Inserting at the front of the list
    myList.push_front(5);
    myList.push_front(15);

    // Removing from the list
    myList.pop_back();
    myList.pop_front();

    // Traversing the list using iterators
    for (const auto& value : myList) {
        cout << value << " ";
    }
    cout << endl;

    return 0;
}

Maps are containers that stores elements in key-value pairs where each key is unique.

maps.cpp

#include <iostream>
#include <map>
using namespace std;

int main() {
    map<string, int> scores;

    // Inserting elements into the map
    scores["Amy"] = 90;
    scores["Daniel"] = 85;
    scores["Charlie"] = 95;

    // Accessing elements
    cout << "Amy's score: " << scores["Amy"];
    cout<<endl;

    // Traversing the map using a for loop
    for (const auto& pair : scores) {
        const string& name = pair.first; // Key
        int score = pair.second; // Value

        cout << name << ": " << score << endl;
    }

    return 0;
}

CppTutorial

Containers

Methods of Vectors:

Deque:

Lists: