What Is Vector Data Structure?

A vector is a dynamic data structure in programming that allows storing and manipulating a collection of elements. It is also known as an array list or a dynamic array. Unlike static arrays, which have fixed sizes, vectors can grow or shrink dynamically as elements are added or removed.

Advantages of using vectors:

• Vectors provide random access to elements, allowing efficient indexing and retrieval.
• They have a flexible size, making them suitable for situations where the number of elements may change during runtime.
• Vectors automatically handle memory management, alleviating the need for manual allocation and deallocation.

Creating a vector:

To create a vector, you need to include the appropriate header file:

#include <vector>

Next, you can declare a vector using the following syntax:

std::vector<data_type> variable_name;

The “data_type” represents the type of elements you want to store in the vector. For example, if you want to store integers, use “int” as the data type. The “variable_name” is the name given to the vector variable.

Adding elements to a vector:

You can add elements to a vector using the “push_back()” function. This function appends an element at the end of the vector. Here’s an example adding integers to a vector:

#include <vector>
#include <iostream>

int main() {
  std::vector<int> numbers;
  
  numbers.push_back(10);
  numbers.push_back(20);
  numbers.push_back(30);
  
  for (int i = 0; i < numbers.size(); i++) {
    std::cout << numbers[i] << " ";
  }
  
  return 0;
}

The output of this code will be: 10 20 30

Accessing elements in a vector:

You can access elements in a vector using the index operator “[]”. The index starts from 0 for the first element and increments by one for each subsequent element. Here’s an example:

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

numbers.push_back(20);

std::cout << numbers[0] << ” “; // Output: 10
std::cout << numbers[1] << ” “; // Output: 20

return 0;
}

Removing elements from a vector:

You can remove elements from a vector using the “pop_back()” function. This function removes the last element from the vector.push_back(20);

std::cout << “Before removal: “;

for (int i = 0; i < numbers.size(); i++) {
std::cout << numbers[i] << ” “;
}

numbers.pop_back();

std::cout << “\nAfter removal: “;

for (int i = 0; i < numbers.size(); i++) {
std::cout << numbers[i] << ” “;
}

return 0;
}

The output of this code will be:

Before removal: 10 20
After removal: 10

Conclusion:

Vectors are an essential data structure in programming that provides dynamic storage and manipulation of elements. With their ability to resize and efficient random access, vectors offer flexibility and convenience in various situations. By understanding how to create, add, access, and remove elements from a vector, you can leverage its power to enhance your programs.