Modifying a Vector

In addition to creating a vector and accessing its elements, the Vector Library provides various methods to modify the vector. These methods allow you to add, remove, and modify elements as needed.

Adding Elements

To add elements to a vector, you can use the push_back() method. This method appends the element to the end of the vector. Here's an example:

1std::vector<int> numbers = {1, 2, 3};
2numbers.push_back(4);

After executing this code, the numbers vector will contain the elements [1, 2, 3, 4].

Modifying Elements

You can modify elements in a vector by accessing them using the subscript operator [] and assigning a new value. Here's an example:

1std::vector<int> numbers = {1, 2, 3, 4};
2numbers[1] = 5;

After executing this code, the numbers vector will contain the elements [1, 5, 3, 4]. The element at index 1 (2) has been replaced with the value 5.

Removing Elements

To remove elements from a vector, you can use the pop_back() method. This method removes the last element from the vector. Here's an example:

1std::vector<int> numbers = {1, 2, 3};
2numbers.pop_back();

After executing this code, the numbers vector will contain the elements [1, 2]. The last element (3) has been removed.

By using these methods, you can easily add, modify, and remove elements in a vector to suit your needs.

Next, we will explore common operations performed on vectors, such as sorting, searching, and merging.

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#include <iostream>

#include <vector>

​

int main() {

    // Creating a vector

    std::vector<int> numbers = {1, 2, 3};

​

    // Adding elements to the vector

    numbers.push_back(4);

​

    // Modifying elements in the vector

    numbers[1] = 5;

​

    // Removing elements from the vector

    numbers.pop_back();

​

    // Printing the vector

    for (int number : numbers) {

        std::cout << number << " ";

    }

    std::cout << std::endl;

​

    return 0;

}