Programming/C++/Objects and Data Structures

Basic Data Structures

Vectors

A vector is a C++ simple class, that effectively acts as a "dynamic array".
It is technically slower and takes more space, but it can be arbitrary sizes.

Creating Vectors

#include <vector>

# Create empty vector.
std::vector<<data_type>> <vector_name>;

# Create vector with some initial data.
std::vector<<data_type>> <vector_name> = {<data_value_1>, <data_value_2>};

# Create vector with some number of elements, but elements aren't populated yet.
std::vector<<data_type>> <vector_name>(<number_of_elements>);

Ex:

#include <vector>

# Create empty vector.
std::vector<int> my_int_vector;

# Create vector with some initial data.
std::vector<int> my_int_vector = {95, 12, 29};

# Create vector with some number of elements, but elements aren't populated yet.
# In this case, 5 elements.
std::vector<int> my_int_vector(5);

Manipulating Vectors

Get vector length:

<vector_var>.size();

Get item at vector index:

...

# Get vector item at a given index.
<vector_var>[<index>];

Ex:

...

# Get vector item at a given index.
# In this case, we get the 6th item, located at index 5 (vectors start at index 0).
my_int_vector[5];

Add item to vector:

...

# Add item to end of vector.
<vector_var>.push_back(<value>);

# Insert item at given vector index.
<vector_var>.insert(<index>, <value>);

Remove item from vector:

...

# Remove item from end of vector (no return value).
<vector_var>.pop_back();

# Remove item at given vector index.
<vector_var>.remove(<index>);