Creation and Use of C Vector - JohnHau/mis GitHub Wiki

What is C++ Vector: STL Basics Vector is a template class in STL (Standard Template Library) of C++ programming language. C++ vectors are sequence containers that store elements.

Specifically used to work with dynamic data, C++ vectors may expand depending on the elements they contain. That makes it different from a fixed-size array.

C++ vectors can automatically manage storage. It is efficient if you add and delete data often. Bear in mind however, that a vector might consume more memory than an array.

Why Use Vectors in C++

Vectors C++ are preferable when managing ever-changing data elements.

It is handy if you don’t know how big the data is beforehand since you don’t need to set the maximum size of the container. Since it’s possible to resize C++ vectors, it offers better flexibility to handle dynamic elements.

C++ vectors offer excellent efficiency. It is a template class, which means no more typing in the same code to handle different data.

If you use vectors, you can copy and assign other vectors with ease. There are different ways to do that: using the iterative method, assignment operator =, an in-built function, or passing vector as a constructor.

In C++ vectors, automatic reallocation happens whenever the total amount of memory is used. This reallocation relates to how size and capacity function works.

How to Create C++ Vectors Vectors in C++ work by declaring which program uses them. The common syntax look like this:

vector variable (elements)

For example:

vector rooms (9);

Let's break it down:

type defines a data type stored in a vector (e.g., , or ) variable is a name that you choose for the data elements specified the number of elements for the data It is mandatory to determine the type and variable name. However, the number of elements is optional.

Basically, all the data elements are stored in contiguous storage. Whenever you want to access or move through the data, you can use iterators.

The data elements in C++ vectors are inserted at the end. Use modifiers to insert new elements or delete existing ones.

Iterators An iterator allows you to access the data elements stored within the C++ vector. It is an object that functions as a pointer. There are five types of iterators in C++: input, output, forward, bidirectional, and random access.

C++ vectors support random access iterators. Here are a few function you may use with iterators for C++ vectors:

vector::begin() returns an iterator to point at the first element of a C++ vector. vector::end() returns an iterator to point at past-the-end element of a C++ vector. vector::cbegin() is similar to vector::begin(), but without the ability to modify the content. vector::cend() issimilar to vector::end() but can’t modify the content.

Modifiers As its name suggests, you can use a modifier to change the meaning of a specified type of data. Here are some modifiers you can use in C++ vectors:

vector::push_back() pushes elements from the back. vector::insert() inserts new elements to a specified location. vector::pop_back() removes elements from the back. vector::erase() removes a range of elements from a specified location. vector::clear() removes all elements.

Breaking It Down With Examples There are many ways to initialize C++ vectors. You can use them depending on your preferences or the size of your data.

C++ Vector: Useful Tips It is recommended to use C++ vector if your data elements are not predetermined. As a template class, C++ vectors offer better efficiency and reusability. Compared to arrays, there are more ways to copy vectors in C++.