std vector c++

The std::vector in C++ is a dynamic array that can grow or shrink in size as needed. It is part of the Standard Template Library (STL) and provides a more flexible alternative to static arrays.

To use std::vector in C++, you need to include the header file at the beginning of your code. This allows you to access the vector class and its functionalities.

To declare a vector, you use the following syntax:

std::vector vectorName;

Replace "DataType" with the type of data you want to store in the vector, such as int, float, or string. Replace "vectorName" with the name you want to give to your vector.

To add elements to the vector, you can use the push_back() function. It appends the element to the end of the vector. For example:

vectorName.push_back(element);

Replace "vectorName" with the name of your vector and "element" with the value you want to add.

To access elements in the vector, you can use the [] operator. It allows you to retrieve elements by their index. Note that indexing starts from 0. For example:

vectorName[index];

Replace "vectorName" with the name of your vector and "index" with the desired index.

To get the size of the vector, you can use the size() function. It returns the number of elements currently stored in the vector. For example:

vectorName.size();

To remove elements from the vector, you can use the erase() function. It removes elements at a specified position or a range of positions. For example:

vectorName.erase(vectorName.begin() + index);

Replace "vectorName" with the name of your vector and "index" with the position of the element you want to remove.

These are just a few of the basic operations you can perform with std::vector in C++. There are many other useful functions available, such as insert(), clear(), and resize(), which allow you to manipulate the vector according to your needs.