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% Document Info
\author{kidchai}
\pdfinfo{
  /Title (oop-key-terms-and-principles.pdf)
  /Creator (Cheatography)
  /Author (kidchai)
  /Subject (OOP key terms and principles Cheat Sheet)
}

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\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
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    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
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\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{OOP key terms and principles Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{kidchai} via \textcolor{DarkBackground}{\uline{cheatography.com/191329/cs/39762/}}}
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\noindent
\begin{multicols}{3}
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  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}kidchai \\
  \uline{cheatography.com/kidchai} \\
  \end{tabulary}
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  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Published 4th August, 2023.\\
   Updated 8th August, 2023.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
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  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
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  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
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\begin{document}
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\begin{multicols*}{2}

\begin{tabularx}{8.4cm}{X}
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\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{OOP}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{Object-oriented programming is a model that organizes software design around objects which interact with each other.% Row Count 3 (+ 3)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
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\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Basic terms}}  \tn
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Class}}} \tn 
% Row Count 1 (+ 1)
% Row 1
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\mymulticolumn{1}{x{8.4cm}}{Data type acting like blueprint for individual objects, attributes, and methods. And rules for interacting with this entity} \tn 
% Row Count 4 (+ 3)
% Row 2
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Objects}}} \tn 
% Row Count 5 (+ 1)
% Row 3
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\mymulticolumn{1}{x{8.4cm}}{Instances of class created with specifically defined data. Object has a state (fields) and behavior (methods).} \tn 
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% Row 4
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Methods}}} \tn 
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\mymulticolumn{1}{x{8.4cm}}{Functions describing behaviors of object.} \tn 
% Row Count 10 (+ 1)
% Row 6
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Attributes}}} \tn 
% Row Count 11 (+ 1)
% Row 7
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\mymulticolumn{1}{x{8.4cm}}{Defined in class template and represent state of object. Object fields.} \tn 
% Row Count 13 (+ 2)
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\mymulticolumn{3}{x{8.4cm}}{\bf\textcolor{white}{Abstract Class | Interface}}  \tn
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 & {\bf{Abstract Class}} & {\bf{Interface}} \tn 
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Describes & Attributes, methods & Methods \tn 
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For classes & With close connections (inheritance) & That could have nothing in common \tn 
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Multiple \seqsplit{Inheritance} & \{\{ac\}\}\{\{fa-close\}\} & \{\{ac\}\}\{\{fa-check\}\} \tn 
% Row Count 9 (+ 2)
% Row 4
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Key words & Implements interface\{\{nl\}\}Extends class & Extends interface \tn 
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\seqsplit{Attributes} & \{\{ac\}\}\{\{fa-check\}\} & \{\{ac\}\}\{\{fa-close\}\} \tn 
% Row Count 14 (+ 2)
% Row 6
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Methods without \seqsplit{realisation} & \{\{ac\}\}\{\{fa-check\}\} (`abstract` keyword) & \{\{ac\}\}\{\{fa-check\}\} \tn 
% Row Count 17 (+ 3)
% Row 7
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Methods with \seqsplit{realisation} & \{\{ac\}\}\{\{fa-check\}\} & \{\{ac\}\}\{\{fa-check\}\} (`default` keyword) \tn 
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\seqsplit{Constructor} & \{\{ac\}\}\{\{fa-check\}\} & \{\{ac\}\}\{\{fa-close\}\} \tn 
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% Row 9
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Access modifiers & any & `public` (default), `private` for methods with realisation \tn 
% Row Count 26 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}---}
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\begin{tabularx}{8.4cm}{X}
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\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{{\bf{Inheritance}} ( "is-a" relationship)}}  \tn
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\mymulticolumn{1}{x{8.4cm}}{We can create a new class based on existing class. The new class can reuse the code and behavior of the ancestor class, and it can also add new features or modify the existing behavior. \newline % Row Count 4 (+ 4)
{\bf{Types:}} \newline % Row Count 5 (+ 1)
• Single (one parent, one child) \newline % Row Count 6 (+ 1)
• Multi-level (child is created from another child) \newline % Row Count 8 (+ 2)
• Multiple (many parents, one child) \newline % Row Count 9 (+ 1)
• Hierarchical (one parent, many children) \newline % Row Count 10 (+ 1)
• Hybrid (child extend several parents, where one or more of them is a combination of different types of inheritance)% Row Count 13 (+ 3)
} \tn 
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\begin{tabularx}{8.4cm}{X}
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\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{{\bf{Encapsulation}} (What happens in Vegas...)}}  \tn
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\mymulticolumn{1}{x{8.4cm}}{By encapsulating a class's variables, only the methods of the class can access them. It protects the data from external access or modification.% Row Count 3 (+ 3)
} \tn 
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\begin{tabularx}{8.4cm}{X}
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\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{{\bf{Polymorphism}}}}  \tn
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\mymulticolumn{1}{x{8.4cm}}{Subclasses can define their own behaviors and yet share some of the same functionality of the parent class.% Row Count 3 (+ 3)
} \tn 
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Compile time polymorphism -{}- Method overloading}} \newline Class can have more than one method with the same name, but with different parameters \newline {\bf{Run time polymorphism - Method overriding}} \newline An instance method in a subclass with the same signature (name, plus the number and the type of its parameters) and return type as an instance method in the superclass overrides the superclass's method.}  \tn 
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\begin{tabularx}{8.4cm}{X}
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\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{{\bf{Abstraction}}}}  \tn
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\mymulticolumn{1}{x{8.4cm}}{We exposing only an object's relevant details to the outside world. And hiding the implementation details. Reduces the code's complexity and makes it easier to use.% Row Count 4 (+ 4)
} \tn 
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\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
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\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Not only Inheritance}}  \tn
% Row 0
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Composition}} "has-a" (strong connection)} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{Building has a room. Containing object owns it. Objects' lifecycles are tied (if we destroy the owner object, its members also will be destroyed with it)} \tn 
% Row Count 5 (+ 4)
% Row 2
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Aggregation}} "has-a" (medium connection)} \tn 
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% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{Сar and its wheels. We can take off the wheels, and they'll still exist. Doesn't involve owning. Lifecycles of the objects aren't tied: every one of them can exist independently of each other.} \tn 
% Row Count 10 (+ 4)
% Row 4
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{Association}} objects "know" each other (weak connection)} \tn 
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% Row 5
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\mymulticolumn{1}{x{8.4cm}}{Mother and child. The difference with aggregation is only logical: whether one of the objects is part of other or not.} \tn 
% Row Count 15 (+ 3)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\begin{tabularx}{8.4cm}{X}
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\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{SOLID principles}}  \tn
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Single Responsibility}}} \tn 
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% Row 1
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\mymulticolumn{1}{x{8.4cm}}{Class should have a single, well-defined responsibility and should not be responsible for multiple things.} \tn 
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Open-Closed}}} \tn 
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\mymulticolumn{1}{x{8.4cm}}{Software enteties (classes, modules, functions) should be open for extension but closed for modification. You should be able to add new functionality to class without changing its existing code.} \tn 
% Row Count 9 (+ 4)
% Row 4
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Liskov Substitution}}} \tn 
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\mymulticolumn{1}{x{8.4cm}}{Objects of a subclass should be able to be used in the same way as objects of parent class without issues.} \tn 
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\mymulticolumn{1}{x{8.4cm}}{{\bf{ Interface Segregation}}} \tn 
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\mymulticolumn{1}{x{8.4cm}}{Classes shouldn't have to implement interfaces that they don't need.} \tn 
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\mymulticolumn{1}{x{8.4cm}}{{\bf{Dependency Inversion}}} \tn 
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% Row 9
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\mymulticolumn{1}{x{8.4cm}}{High-level modules (i.e., classes depending on other classes) should not depend on low-level modules. Both should depend on abstractions. So, it's easier to change implementation of low-level module without affecting high-level module.} \tn 
% Row Count 22 (+ 5)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
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% That's all folks
\end{multicols*}

\end{document}