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% Document Info
\author{EllieAtWHL (EllieAtWHL)}
\pdfinfo{
  /Title (salesforce-javascript-functional.pdf)
  /Creator (Cheatography)
  /Author (EllieAtWHL (EllieAtWHL))
  /Subject (Salesforce Javascript Functional Cheat Sheet)
}

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    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Salesforce Javascript Functional Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{EllieAtWHL (EllieAtWHL)} via \textcolor{DarkBackground}{\uline{cheatography.com/120941/cs/21955/}}}
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  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}EllieAtWHL (EllieAtWHL) \\
  \uline{cheatography.com/ellieatwhl} \\
        \uline{\seqsplit{trailblazer}.me/id/elliematthewman}
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  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Published 6th March, 2020.\\
   Updated 7th April, 2021.\\
   Page {\thepage} of \pageref{LastPage}.
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  %\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{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Arrow Functions (Fat Arrows)}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{Arrow functions create a concise expression that encapsulates a small piece of functionality. Additionally, arrows retain the scope of the caller inside the function eliminating the need of self = this. \newline % Row Count 5 (+ 5)
{\bf{Example}} \newline % Row Count 6 (+ 1)
`// const multiply = function(x,y) \{` \newline % Row Count 7 (+ 1)
`// ~ return x * y;` \newline % Row Count 8 (+ 1)
`// \}` \newline % Row Count 9 (+ 1)
`// Can be rewritten as:` \newline % Row Count 10 (+ 1)
`// const multiply = (x, y) =\textgreater{} \{ return x * y \};` \newline % Row Count 11 (+ 1)
`// Since the function is a single expression return and braces are not needed.` \newline % Row Count 13 (+ 2)
`const multiply = (x, y) =\textgreater{} x * y;` \newline % Row Count 14 (+ 1)
`console.log(multiply(5,10)) //50`% Row Count 15 (+ 1)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Function Delegates}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{Function delegates encapsulate a method allowing functions to be composed or passed as data. \newline % Row Count 2 (+ 2)
{\bf{Example}} \newline % Row Count 3 (+ 1)
`const isZero = n =\textgreater{} n === 0;` \newline % Row Count 4 (+ 1)
`const a = {[}0,1,0,3,4,0{]};` \newline % Row Count 5 (+ 1)
\seqsplit{`console.log(a.filter(isZero).length);} // 3`% Row Count 6 (+ 1)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Expressions Instead of Statements}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{Statements define an action and are executed for their side effect. Expressions produce a result without mutating state. \newline % Row Count 3 (+ 3)
{\bf{Statement}} \newline % Row Count 4 (+ 1)
`const getSalutation = function(hour) \{` \newline % Row Count 5 (+ 1)
`~var salutation; // temp value` \newline % Row Count 6 (+ 1)
`~if (hour \textless{} 12) \{` \newline % Row Count 7 (+ 1)
`~~ salutation = "Good Morning";` \newline % Row Count 8 (+ 1)
`\}` \newline % Row Count 9 (+ 1)
`~else \{` \newline % Row Count 10 (+ 1)
`~~ salutation = "Good Afternoon"` \newline % Row Count 11 (+ 1)
`\}` \newline % Row Count 12 (+ 1)
`~return salutation; // mutated value` \newline % Row Count 13 (+ 1)
`\}` \newline % Row Count 14 (+ 1)
{\bf{Expression}} \newline % Row Count 15 (+ 1)
`const getSalutation = (hour) =\textgreater{} hour \textless{} 12 ? "Good Morning" : "Good Afternoon";` \newline % Row Count 17 (+ 2)
\seqsplit{`console.log(getSalutation(10));} // Good Morning'`% Row Count 18 (+ 1)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Higher Order Functions}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{A function that accepts another function as a parameter, or returns another function. \newline % Row Count 2 (+ 2)
{\bf{Example}} \newline % Row Count 3 (+ 1)
`function mapConsecutive(values, fn) \{` \newline % Row Count 4 (+ 1)
`~let result = {[}{]};` \newline % Row Count 5 (+ 1)
`~for(let i=0; i \textless{} values.length -1; i++) \{` \newline % Row Count 6 (+ 1)
`~~result.push(fn(values{[}i{]}, values{[}i+1{]}));` \newline % Row Count 8 (+ 2)
`~\}` \newline % Row Count 9 (+ 1)
`~return result;` \newline % Row Count 10 (+ 1)
`\}` \newline % Row Count 11 (+ 1)
`const letters = {[}'a','b','c','d','e','f','g'{]};` \newline % Row Count 12 (+ 1)
`let twoByTwo = mapConsecutive(letters, (x,y) =\textgreater{} {[}x,y{]});` \newline % Row Count 14 (+ 2)
`console.log(twoByTwo);` \newline % Row Count 15 (+ 1)
`// {[}{[}a,b{]}, {[}b,c{]}, {[}c,d{]}, {[}d,e{]}, {[}e,f{]}, {[}f,g{]}{]}`% Row Count 16 (+ 1)
} \tn 
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\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Method Chaining}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{Method chains allow a series of functions to operate in succession to reach a final result. Method chains allow \newline % Row Count 3 (+ 3)
function composition similar to a pipeline. \newline % Row Count 4 (+ 1)
{\bf{Example}} \newline % Row Count 5 (+ 1)
`let cart = {[}\{name: "Drink", price: 3.12\},` \newline % Row Count 6 (+ 1)
`~\{name: "Steak", price: 45.15\},` \newline % Row Count 7 (+ 1)
`~\{name: "Drink", price: 11.01\}{]};` \newline % Row Count 8 (+ 1)
`let drinkTotal = cart.filter(x=\textgreater{} x.name === "Drink")` \newline % Row Count 10 (+ 2)
`~.map(x=\textgreater{} x.price)` \newline % Row Count 11 (+ 1)
`~.reduce((t,v) =\textgreater{} t +=v)` \newline % Row Count 12 (+ 1)
`~.toFixed(2);` \newline % Row Count 13 (+ 1)
`console.log(Total Drink Cost \$\$\{drinkTotal\}); // Total Drink Cost \$14.13`% Row Count 15 (+ 2)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Currying}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{Currying allows a function with multiple arguments to be translated into a sequence of functions. Curried functions can be tailored to match the signature of another function. \newline % Row Count 4 (+ 4)
{\bf{Example}} \newline % Row Count 5 (+ 1)
`const convertUnits = (toUnit, factor, offset = 0) =\textgreater{} input =\textgreater{} ((offset + input) *` \seqsplit{`factor).toFixed(2).concat(toUnit);`} \newline % Row Count 8 (+ 3)
`const milesToKm = convertUnits('km', 1.60936, 0);` \newline % Row Count 10 (+ 2)
`const poundsToKg = convertUnits('kg', 0.45460, 0);` \newline % Row Count 12 (+ 2)
`const farenheitToCelsius = convertUnits('degrees C', 0.5556, -32);` \newline % Row Count 14 (+ 2)
`milesToKm(10); //"16.09 km"` \newline % Row Count 15 (+ 1)
`poundsToKg(2.5); //"1.14 kg"` \newline % Row Count 16 (+ 1)
`farenheitToCelsius(98); //"36.67 degrees C"` \newline % Row Count 17 (+ 1)
`const weightsInPounds = {[}5,15.4,9.8, 110{]};` \newline % Row Count 18 (+ 1)
`// const weightsInKg = weightsInPounds.map(x =\textgreater{} convertUnits('kg', 0.45460,` \newline % Row Count 20 (+ 2)
`0)(x));` \newline % Row Count 21 (+ 1)
`// with currying` \newline % Row Count 22 (+ 1)
`const weightsInKg = \seqsplit{weightsInPounds.map(poundsToKg);`} \newline % Row Count 24 (+ 2)
`// 2.27kg, 7.00kg, 4.46kg, 50.01kg`% Row Count 25 (+ 1)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
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\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Array Manipulation Functions}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{Array Functions are the gateway to functional programming in JavaScript. These functions make short work of most imperative programming routines that work on arrays and collections. \newline % Row Count 4 (+ 4)
`{[}{]}.every(fn)` \newline % Row Count 5 (+ 1)
Checks if all elements in an array pass a test. \newline % Row Count 6 (+ 1)
`{[}{]}.some(fn)` \newline % Row Count 7 (+ 1)
Checks if any of the elements in an array pass a test. \newline % Row Count 9 (+ 2)
`{[}{]}.find(fn)` \newline % Row Count 10 (+ 1)
Returns the value of the first element in the array that passes a test. \newline % Row Count 12 (+ 2)
`{[}{]}.filter(fn)` \newline % Row Count 13 (+ 1)
Creates an array filled with only the array elements that pass a test. \newline % Row Count 15 (+ 2)
`{[}{]}.map(fn)` \newline % Row Count 16 (+ 1)
Creates a new array with the results of a function applied to every element in the array. \newline % Row Count 18 (+ 2)
`{[}{]}.reduce(fn(accumulator, currentValue))` \newline % Row Count 19 (+ 1)
Executes a provided function for each value of the array (from left-to-right). Returns a single value, the accumulator. \newline % Row Count 22 (+ 3)
`{[}{]}.sort(fn(a,b))` {\emph{warning, mutates state!}} \newline % Row Count 23 (+ 1)
Modifies an array by sorting the items within an array. An optional compare function can be used to customize sort behaviour. Use the spread operator to avoid mutation. `{[}...arr{]}.sort()` \newline % Row Count 27 (+ 4)
`{[}{]}.reverse()` {\emph{warning, mutates state!}} \newline % Row Count 28 (+ 1)
Reverses the order of the elements in an array. Use the spread operator to avoid mutation. `{[}...arr{]}.reverse()`% Row Count 31 (+ 3)
} \tn 
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\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Pipelines}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{A pipeline allows for easy function composition when performing multiple operations on a variable. Since JavaScript lacks a Pipeline operator, a design pattern can be used to accomplish the task. \newline % Row Count 4 (+ 4)
{\bf{Example}} \newline % Row Count 5 (+ 1)
`const pipe = functions =\textgreater{} data =\textgreater{} \{` \newline % Row Count 6 (+ 1)
`~return functions.reduce(` \newline % Row Count 7 (+ 1)
`~~(value, func) =\textgreater{} func(value),` \newline % Row Count 8 (+ 1)
`~data` \newline % Row Count 9 (+ 1)
`~);` \newline % Row Count 10 (+ 1)
`\};` \newline % Row Count 11 (+ 1)
`let cart = {[}3.12, 45.15, 11.01{]};` \newline % Row Count 12 (+ 1)
`const addSalesTax = (total, taxRate) =\textgreater{} (total * taxRate) + total;` \newline % Row Count 14 (+ 2)
`const tally = orders =\textgreater{} pipe({[}` \newline % Row Count 15 (+ 1)
`x =\textgreater{} x.reduce((total, val) =\textgreater{} total + val), // sum the order` \newline % Row Count 17 (+ 2)
`x =\textgreater{} addSalesTax(x, 0.09),` \newline % Row Count 18 (+ 1)
`x =\textgreater{} Order Total = \$\{x.toFixed(2)\} // convert to text` \newline % Row Count 20 (+ 2)
`{]})(orders); // Order Total = 64.62`% Row Count 21 (+ 1)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}



\end{document}