\documentclass[10pt,a4paper]{article}

% Packages
\usepackage{fancyhdr}           % For header and footer
\usepackage{multicol}           % Allows multicols in tables
\usepackage{tabularx}           % Intelligent column widths
\usepackage{tabulary}           % Used in header and footer
\usepackage{hhline}             % Border under tables
\usepackage{graphicx}           % For images
\usepackage{xcolor}             % For hex colours
%\usepackage[utf8x]{inputenc}    % For unicode character support
\usepackage[T1]{fontenc}        % Without this we get weird character replacements
\usepackage{colortbl}           % For coloured tables
\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{peternorvigpro}
\pdfinfo{
  /Title (swift-4.pdf)
  /Creator (Cheatography)
  /Author (peternorvigpro)
  /Subject (swift 4 Cheat Sheet)
}

% Lengths and widths
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\addtolength{\hoffset}{-3cm}
\addtolength{\voffset}{-2cm}
\setlength{\tabcolsep}{0.2cm} % Space between columns
\setlength{\headsep}{-12pt} % Reduce space between header and content
\setlength{\headheight}{85pt} % If less, LaTeX automatically increases it
\renewcommand{\footrulewidth}{0pt} % Remove footer line
\renewcommand{\headrulewidth}{0pt} % Remove header line
\renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit
% This two commands together give roughly
% the right line height in the tables
\renewcommand{\arraystretch}{1.3}
\onehalfspacing

% Commands
\newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour
\newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols
\newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns
\newcommand{\tn}{\tabularnewline} % Required as custom column type in use

% Font and Colours
\definecolor{HeadBackground}{HTML}{333333}
\definecolor{FootBackground}{HTML}{666666}
\definecolor{TextColor}{HTML}{333333}
\definecolor{DarkBackground}{HTML}{82A395}
\definecolor{LightBackground}{HTML}{F7F9F8}
\renewcommand{\familydefault}{\sfdefault}
\color{TextColor}

% Header and Footer
\pagestyle{fancy}
\fancyhead{} % Set header to blank
\fancyfoot{} % Set footer to blank
\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{swift 4 Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{peternorvigpro} via \textcolor{DarkBackground}{\uline{cheatography.com/66685/cs/16661/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}peternorvigpro \\
  \uline{cheatography.com/peternorvigpro} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 14th August, 2018.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{2}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Function}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{typealias operation = (Int, Int) -\textgreater{} (Int) \newline  \newline // parameters: constant (pass by value) \newline // want to modify? \newline func modifyParams(\_ value: inout Int) \{\} \newline var value = 1 \newline modifyParams(\&value) \newline  \newline // overloading external parameter names \newline func multipleOf(\_ multiplier: Int, and value: Int) \{\} \newline func multipleOf(multiplier: Int, value: Int) \{\} \newline  \newline // overloading return value \newline func getValue() -\textgreater{} Int \newline func getValue() -\textgreater{} String \newline let value: Int = getValue()} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Basic types}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{// \{\{link="https://developer.apple.com/documentation/swift/range"\}\}Range\{\{/link\}\} \newline let range1 = 0...2 \newline let range2 = 0..\textless{}2 \newline  \newline // \{\{link="https://developer.apple.com/documentation/swift/array"\}\}Array\{\{/link\}\} \newline let arr1: {[}Int{]} = {[}1,2,3{]} \newline let arr2: Array\textless{}Int\textgreater{} = {[}1,2,3{]} \newline  \newline arr.first //=\textgreater{} Optional \newline arr{[}0{]} //=\textgreater{} value (maybe crash if wrong index) \newline  \newline arr{[}0...2{]} = {[}1,2,3{]} \newline arr{[}0...2{]} = {[}1,2,3,4,5{]} // still works \newline  \newline for item in arr \{\} \newline for (index, item) in arr.enumerated() \{\} \newline  \newline // \{\{link="https://developer.apple.com/documentation/swift/dictionary"\}\}Dictionary\{\{/link\}\} \newline let dic {[}String: Int{]} = {[}"alpha": 1, "beta": 2{]} \newline let dic Dictionary\textless{}String, Int\textgreater{} \newline  \newline dic{[}"unknow"{]} //=\textgreater{} nil \newline  \newline for (key, value) in dic \{\} \newline for key in dic.keys \{\} \newline  \newline // \{\{link="https://developer.apple.com/documentation/swift/set"\}\}Set\{\{/link\}\} \newline let set: Set\textless{}Int\textgreater{} = {[}1,2,3{]} \newline  \newline // \{\{link="http://goshdarnclosuresyntax.com/"\}\}Closure\{\{/link\}\} \newline var addClosure: (Int, Int) -\textgreater{} Int \newline // long form \newline addClosure = \{ (a: Int, b: Int) -\textgreater{} Int in \newline   return a + b \newline \} \newline // short form use type inference \newline addClosure = \{ (a, b) in  \newline   return a + b \newline \} \newline // even shorter     \$0 = a, \$1 = b \newline addClosure = \{ \newline   return \$0 + \$1 \newline \} \newline // shortest - omit "return" if immediately return \newline addClosure = \{ \newline   \$0 + \$1 \newline \} \newline  \newline // when closure is the last parameter \newline // common syntax \newline arr.filter \{ item -\textgreater{} Bool in \newline   return !!item \newline \} \newline var stock = {[}1.5: 5, 2.5: 10{]} \newline let sum = stock.reduce(0) \{ result, pair -\textgreater{} Double in  \newline   return result + (pair.key * Double(pair.value)) \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Optional}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{// either value or nil \newline var optional: String? \newline  \newline // some func return optional \newline var parseInt = Int("1")                         // 1 \newline var parseInt = Int("something ugly")   // nil \newline  \newline // maybe surprise \newline var optInt: Int? = 10 \newline print(optInt) // Optional(10) \newline optInt + 1    // error. Must be unwrapped \newline  \newline // Avoid \newline // unwrapped with ! \newline var unwrappedOptInt = optInt! // 1 or crash if optInt == nil \newline  \newline // Use this \newline // optional binding \newline if let unwrappedOptInt = optInt \{\} else \{\} \newline  \newline // can shadow like this (temporary access) \newline if let optInt = optInt \{\} else \{\} \newline  \newline // multiple unwrap \newline if let optInt = optInt, let optStr = optStr \{\} \newline  \newline // (better) use guard \newline // also better for optimization \textless{}- don't know why. find out later \newline let optFunc: () -\textgreater{} Int? \newline func takeMeIn() \{ \newline   guard let optFunc = optFunc() else \{ \newline      // when optFunc is nil \newline      return // guard must be returned or throw \newline   \} \newline   // when optFunc is Int \newline \} \newline  \newline // Nil Coalescing \newline let result = optInt ?? 0} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}