Methods available with vector in C++

 The vector class in C++ provides various methods to perform different operations on vectors. Here are some commonly used methods:

1. push_back(): Inserts a new element at the end of the vector.
2. pop_back(): Removes the last element from the vector.
3. size(): Returns the number of elements in the vector.
4. empty(): Returns true if the vector is empty.
5. clear(): Removes all elements from the vector.
6. begin(): Returns an iterator pointing to the first element of the vector.
7. end(): Returns an iterator pointing to the past-the-end element of the vector.
8. insert(): Inserts an element at a specified position in the vector.
9. erase(): Removes an element from a specified position in the vector.
10. resize(): Resizes the vector to a specified size.
11. swap(): Swaps the contents of two vectors.
12. at(): Returns a reference to the element at a specified position in the vector.
13. front(): Returns a reference to the first element in the vector.
14. back(): Returns a reference to the last element in the vector.
15. data(): Returns a direct pointer to the memory array used internally by the vector.

Here's an example code snippet that demonstrates the usage of some of these methods:

#include <iostream>
#include <vector>

int main() {
    std::vector<int> vec;

    // Insert elements using push_back()
    vec.push_back(10);
    vec.push_back(20);
    vec.push_back(30);

    // Access elements using indexing
    std::cout << "Element at index 1: " << vec[0] << std::endl;

    // Access elements using at()
    std::cout << "Element at index 2: " << vec.at(2) << std::endl;

    // Size of the vector
    std::cout << "Size of the vector: " << vec.size() << std::endl;

    // Check if the vector is empty
    if (vec.empty()) {
        std::cout << "Vector is empty" << std::endl;
    } else {
        std::cout << "Vector is not empty" << std::endl;
    }

    // Clear the vector
    vec.clear();

    // Check if the vector is empty after clearing
    if (vec.empty()) {
        std::cout << "Vector is empty" << std::endl;
    } else {
        std::cout << "Vector is not empty" << std::endl;
    }

    return 0;
}
Element at index 1: 20
Element at index 2: 30
Size of the vector: 3
Vector is not empty
Vector is empty
Please note that this is not an exhaustive list of all the methods available with the vector class. You can refer to the C++ documentation or the provided sources for more information on the vector class and its methods.