Program 11 BCA Madras University BCA Object Oriented Programming using C++ Practical Madras University Program 11 Demonstrate the use of the vector STL container.

 

BCA

Object Oriented Programming using C++ Practical

Madras University 

Program 11

Demonstrate the use of the vector STL container.

SOURCE CODE:

#include <iostream>

#include <vector>

using namespace std;

int main() {

    // Create a vector of integers

    vector<int> numbers;

    // Add elements to the vector

    numbers.push_back(1);

    numbers.push_back(2);

    numbers.push_back(3);

    // Access elements using an index

    cout << "The first element is: " << numbers[0] << endl;

    // Iterate over the vector and print each element

    cout << "The elements in the vector are: ";

    for (const int& num : numbers) {

        cout << num << " ";

    }

    cout << endl;

    // Remove the last element

    numbers.pop_back();

    // Print the size of the vector

    cout << "The size of the vector after pop_back is: " << numbers.size() << endl;

    // Check if the vector is empty

    if (numbers.empty()) {

        cout << "The vector is empty." << endl;

    } else {

        cout << "The vector is not empty." << endl;

    }

    return 0;

}

OUTPUT:

The first element is: 1

The elements in the vector are: 1 2 3

The size of the vector after pop_back is: 2

The vector is not empty.

Explanation:

1. Include the Header: #include <vector> is necessary to use the std::vector class.
2. Create a Vector: std::vector<int> numbers; creates a vector of integers.
3. Add Elements: push_back adds elements to the end of the vector.
4. Access Elements: You can use the subscript operator [] to access elements.
5. Iterate Over Elements: A range-based for loop is used to print all elements.
6. Remove Elements: pop_back removes the last element.
7. Check Size: size() returns the number of elements in the vector.
8. Check if Empty: empty() returns true if the vector has no elements.