{"id":554,"date":"2020-04-08T01:58:06","date_gmt":"2020-04-08T01:58:06","guid":{"rendered":"http:\/\/pragmaticways.com\/?p=554"},"modified":"2021-01-26T05:29:01","modified_gmt":"2021-01-26T05:29:01","slug":"refactor-code-for-a-pizza-ordering-service","status":"publish","type":"post","link":"https:\/\/pragmaticways.com\/refactor-code-for-a-pizza-ordering-service\/","title":{"rendered":"Refactoring code for a pizza ordering service"},"content":{"rendered":"\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe title=\"Beginner&#039;s tutorial on refactoring code (how to write clean code)\" width=\"640\" height=\"360\" src=\"https:\/\/www.youtube.com\/embed\/IM3zOyGeRFs?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p>This is a <strong>beginner level<\/strong> tutorial on refactoring some old code I wrote a while ago. If you want to submit a homework assignment for a code review to be featured on Pragmatic Ways, you can join our Facebook Group and post your suggestion: <a href=\"https:\/\/www.facebook.com\/groups\/PragmaticWaysSoftwareEngineers\/\" class=\"rank-math-link\">Software Engineering Mastermind Group<\/a><\/p>\n\n\n\n<p>Note: This program is written in C++, but the language or technology doesn&#8217;t really matter here. We&#8217;re not focusing on C++ specific details, we&#8217;re focusing on <strong>fundamental programming concepts to writing cleaner code<\/strong>. <\/p>\n\n\n\n<p>Also note: This is a very basic example of refactoring with only a few tips on code cleanup. This example could be taken much farther, but to do so would require covering more advanced concepts that were not yet introduced prior to this assignment. This is a tutorial with a target audience for beginners who are starting out learning how to code. <\/p>\n\n\n\n<div class=\"wp-block-columns\">\n<div class=\"wp-block-column\">\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/amzn.to\/39SseVo\" target=\"_blank\" rel=\"noopener noreferrer\"><img loading=\"lazy\" width=\"1024\" height=\"769\" src=\"http:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/refactoring_book-1024x769.jpg\" alt=\"best book on refactoring code\" class=\"wp-image-569\" srcset=\"https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/refactoring_book-1024x769.jpg 1024w, https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/refactoring_book-300x225.jpg 300w, https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/refactoring_book-768x577.jpg 768w, https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/refactoring_book-1536x1154.jpg 1536w, https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/refactoring_book-2048x1539.jpg 2048w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column\">\n<p><strong>How to refactor code<\/strong><\/p>\n\n\n\n<ul><li><a href=\"https:\/\/amzn.to\/39SseVo\" class=\"rank-math-link\">Buy this book<\/a><\/li><li>Read this book<\/li><li>Master this book<\/li><li>Master your career<\/li><li>Master your life<\/li><\/ul>\n\n\n\n<p>&gt;&gt;&gt; <a href=\"https:\/\/amzn.to\/39SseVo\" class=\"rank-math-link\">Click here to purchase the Refactoring Book<\/a> <\/p>\n<\/div>\n<\/div>\n\n\n\n<h2>Program Requirements<\/h2>\n\n\n\n<p>Joe\u2019s Pizza Palace needs a program to calculate the number of slices a pizza of any size can be divided into. The program should also report the number of pizzas someone should order for a party. Assume each person at the party will eat 3 slices each. The program should prompt the user for the diameter of the pizzas they wish to order and the number of people who will be at the party. The program should then calculate and display the number of slices per pizza and the number of pizzas needed for the party.   <\/p>\n\n\n\n<ul><li>A slice must have an area of 14.125 inches  <\/li><li>Number of slices per pizza is the area of the pizza divided by the area of a slice  <\/li><li>Area of a pizza is calculated with Area = PI * r^2 where PI = 3.14159 and r is the radius of the pizza  <\/li><li>The number of slices should be fixed point and rounded to one decimal place  <\/li><li>PI must be a named constant<\/li><\/ul>\n\n\n\n<p>(Note: these program requirements came from home assignment in the book <a target=\"_blank\" href=\"https:\/\/www.amazon.com\/gp\/product\/B00IUQV4M4\/ref=as_li_tl?ie=UTF8&amp;camp=1789&amp;creative=9325&amp;creativeASIN=B00IUQV4M4&amp;linkCode=as2&amp;tag=selftaughtadu-20&amp;linkId=5a35a128727e99156d3dfd97d1d82c3a\" rel=\"noopener noreferrer\">Starting Out with C++: From Control Structures through Objects<\/a><img loading=\"lazy\" src=\"\/\/ir-na.amazon-adsystem.com\/e\/ir?t=selftaughtadu-20&amp;l=am2&amp;o=1&amp;a=B00IUQV4M4\" width=\"1\" height=\"1\" border=\"0\" alt=\"\" style=\"border:none !important; margin:0px !important;\">)<\/p>\n\n\n\n<h2>Original Source Code<\/h2>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-1\" data-shcb-language-name=\"PHP\" data-shcb-language-slug=\"php\"><div><code lang=\"cpp\" class=\"hljs language-php language-cpp\"><span class=\"hljs-keyword\">include<\/span> \n <span class=\"hljs-keyword\">include<\/span> \n <span class=\"hljs-keyword\">include<\/span> \n using <span class=\"hljs-keyword\">namespace<\/span> <span class=\"hljs-title\">std<\/span>;\n int main() {\n     <span class=\"hljs-keyword\">const<\/span> double PI = <span class=\"hljs-number\">3.14159<\/span>,\n                  SLICE_AREA = <span class=\"hljs-number\">14.125<\/span>;\n     double  pizzaRad,\n             pizzaArea,\n             numSlicesPerPizza;\n     int slicesPerPerson = <span class=\"hljs-number\">3<\/span>,\n         numPeople,\n         numPizzasNeed,\n         pizzaDi;\n &lt;code&gt;<span class=\"hljs-comment\">\/\/ prompt user for pizza and party info cout &lt;&lt; \"What size pizza would you like? (Enter the inch diameter of the pizza)\\n\"; cin &gt;&gt; pizzaDi; cout &lt;&lt; \"How many people are at the party?\\n\"; cin &gt;&gt; numPeople; \/\/ calculations  pizzaRad = pizzaDi \/ 2; pizzaArea = PI * pow(pizzaRad, 2.0); numSlicesPerPizza = pizzaArea \/ SLICE_AREA; numPizzasNeed = ((numPeople * slicesPerPerson) \/ numSlicesPerPizza) + 1; \/\/ display the results.  cout &lt;&lt; endl; cout &lt;&lt; \"Pizza Size: \"        &lt;&lt; right &lt;&lt; setw(10) &lt;&lt; pizzaDi &lt;&lt; endl; cout &lt;&lt; \"Number of slices: \"  &lt;&lt; right &lt;&lt; setw(4) &lt;&lt; setprecision(1) &lt;&lt; fixed &lt;&lt; showpoint &lt;&lt; numSlicesPerPizza &lt;&lt; endl; cout &lt;&lt; \"Number of people: \"  &lt;&lt; right &lt;&lt; setw(4) &lt;&lt; numPeople &lt;&lt; endl; cout &lt;&lt; \"Number of pizzas: \"  &lt;&lt; right &lt;&lt; setw(4) &lt;&lt; numPizzasNeed &lt;&lt; endl &lt;&lt; endl; system(\"pause\"); return 0;&lt;\/code&gt;<\/span>\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-1\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PHP<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">php<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h2>Refactoring Efforts<\/h2>\n\n\n\n<p>Now let&#8217;s see how we can refactor this code and clean some of it up. Before we actually dive into the implementation of things, let&#8217;s start by listing some of the issues we see with this program. <\/p>\n\n\n\n<ol><li>The <code class=\"pragmatic-ways\">main<\/code> function is handling 100% of the logic. It would be better to separate this logic into multiple functions that each handle a specific piece of the logic<\/li><li>It&#8217;s declaring all of the variables at the beginning, when many of them are only used once or twice for a specific purpose. We should reduce the scope of these variables to the lowest possible visibility<\/li><li>The variable names aren&#8217;t terrible, but could be a little more explicit<\/li><\/ol>\n\n\n\n<p>Let&#8217;s start by extracting some of the logic from the <code class=\"pragmatic-ways\">main<\/code> function into separate functions. <\/p>\n\n\n\n<h3>Extracting the user input<\/h3>\n\n\n\n<p>The first actual piece of logic that&#8217;s happening is getting the user&#8217;s input for the <code class=\"pragmatic-ways\">pizzaDi<\/code> and <code class=\"pragmatic-ways\">numPeople<\/code> variables. Let&#8217;s move these into their own functions. <\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-2\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><div><code lang=\"cpp\" class=\"hljs language-javascript language-cpp\">int getPizzaDiameterFromUser() {\n   int pizzaDiameter;\n   cout &lt;&lt; <span class=\"hljs-string\">\"What size pizza would you like? (Enter the inch diameter of the pizza)\\n\"<\/span>;   cin &gt;&gt; pizzaDiameter;\n   <span class=\"hljs-keyword\">return<\/span> pizzaDiameter;\n }\n int getNumberOfPeopleFromUser() {\n   int numberOfPeople;\n   cout &lt;&lt; <span class=\"hljs-string\">\"How many people are at the party?\\n\"<\/span>;   cin &gt;&gt; numberOfPeople;\n   <span class=\"hljs-keyword\">return<\/span> numberOfPeople;\n }\n int main() {\n   \u2026\n   int pizzaDiameter = getPizzaDiameterFromUser();\n   int numberOfPeople = getNumberOfPeopleFromUser();\n   \u2026\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-2\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Here I removed the declaration of the variables from the top of the function to declaring and initializing them for when I actually need to. We should always be focusing on <strong>declaring variables as close to their initialization and use as possible<\/strong>, and by extracting out this logic into a separate function, I&#8217;m now able to declare and initialize these variables on the same line in the main function. <\/p>\n\n\n\n<p>Note: I also made the variables names a tiny bit more explicit. It&#8217;s not a huge difference, but the tiny bit of more information just helps with the readability of the code. <\/p>\n\n\n\n<p>Now before we move on, hopefully you&#8217;ve noticed something about these two functions. Go ahead and take another look at these new functions we just created. Do you see it? Did you notice how these 2 functions are almost identical? The logic between both functions are nearly identical, and this is considered <a href=\"http:\/\/pragmaticways.com\/31-code-smells-you-must-know\/#2_Duplicate_Code\" class=\"rank-math-link\">duplicate code<\/a>. Let&#8217;s clean up this code duplication before moving forward by creating a new function. <\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-3\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><div><code lang=\"cpp\" class=\"hljs language-javascript language-cpp\">int getUserInput(string message) {\n   int userInput;\n   cout &lt;&lt; message;   cin &gt;&gt; userInput;\n   <span class=\"hljs-keyword\">return<\/span> userInput;\n }\n int getPizzaDiameterFromUser() {\n   <span class=\"hljs-keyword\">return<\/span> getUserInput(<span class=\"hljs-string\">\"What size pizza would you like? (Enter the inch diameter of the pizza)\\n\"<\/span>);\n }\n int getNumberOfPeopleFromUser() {\n   <span class=\"hljs-keyword\">return<\/span> getUserInput(<span class=\"hljs-string\">\"How many people are at the party?\\n\"<\/span>);\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-3\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Now we&#8217;ve taken the duplicate code from the <code class=\"pragmatic-ways\">getPizzaDiameterFromUser()<\/code> and <code class=\"pragmatic-ways\">getNumberOfPeopleFromUser()<\/code> functions and extracted out what&#8217;s common between the two into the separate, generic function <code class=\"pragmatic-ways\">getUserInput()<\/code>.<\/p>\n\n\n\n<h3>Extracting the calculations<\/h3>\n\n\n\n<p>Next we&#8217;ll move the calculations into their own functions. There&#8217;s a lot of implementation logic and their required variables in the <code class=\"pragmatic-ways\">main<\/code> function that really doesn&#8217;t need to be there. The <code class=\"pragmatic-ways\">main<\/code> function is a high-level component, when things like the <code class=\"pragmatic-ways\">PI<\/code> constant and <code class=\"pragmatic-ways\">pizzaArea<\/code> variable are lower level implementation details. <\/p>\n\n\n\n<p>It&#8217;s always best to hide the low level implementation details into lower level functions. This makes it easier for others to quickly scan the code from a high overview.<\/p>\n\n\n\n<p>Realistically, if we look at our requirements again, the only things we need to do are to &#8220;calculate and display the number of slices per pizza and the number of pizzas needed for the party.&#8221; That&#8217;s all we need to do from a high level overview, so let&#8217;s keep our <code class=\"pragmatic-ways\">main<\/code> function at a high level overview and only show those details. <\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-4\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><div><code lang=\"cpp\" class=\"hljs language-javascript language-cpp\">int main() {\n   double numberOfSlicesPerPizza = calcNumSlicesPerPizza();\n   int numPizzasNeeded = calcNumPizzasNeeded(numberOfSlicesPerPizza);\n displayResults(numberOfSlicesPerPizza, numPizzasNeeded);\n <span class=\"hljs-keyword\">return<\/span> <span class=\"hljs-number\">0<\/span>;\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-4\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Now anyone wanting to see what our program does can quickly and easily look at the <code class=\"pragmatic-ways\">main<\/code> function and understand what this program does. If they want to see <em>how<\/em> it&#8217;s actually doing it, they can dig further into the lower level implementation details. Let&#8217;s build those out now to see what they&#8217;d look like. <\/p>\n\n\n\n<h4>Calculate the number of slices per pizza<\/h4>\n\n\n\n<p>What do we actually need to implement this function? From our requirements, we see that the &#8220;number of slices per pizza is the area of the pizza divided by the area of a slice.&#8221; We&#8217;re also already told that &#8220;a slice must have an area of 14.125 inches.&#8221; So let&#8217;s keep this function as simple as possible, and just follow what the requirements tell us. <\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-5\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><div><code lang=\"cpp\" class=\"hljs language-javascript language-cpp\">double calcNumSlicesPerPizza() {\n   double pizzaArea = calculatePizzaArea();\n   <span class=\"hljs-keyword\">const<\/span> double SLICE_AREA = <span class=\"hljs-number\">14.125<\/span>;  \n   <span class=\"hljs-keyword\">return<\/span> pizzaArea \/ SLICE_AREA;\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-5\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>What&#8217;s nice about this function is we isolated the&nbsp;<code class=\"pragmatic-ways\">SLICE_AREA<\/code>&nbsp;constant to just the 3 lines of code that actually need it. It&#8217;s now completely hidden from the&nbsp;<code class=\"pragmatic-ways\">main<\/code>&nbsp;function, just the way it should be. We don&#8217;t even need to know about the&nbsp;<code class=\"pragmatic-ways\">calculatePizzaArea()<\/code>&nbsp;details here, all we care about in the&nbsp;<code class=\"pragmatic-ways\">calcNumSlicesPerPizza()<\/code>&nbsp;function is that we are getting the area of a pizza.<\/p>\n\n\n\n<p>Let&#8217;s now dive deeper and build out this <code class=\"pragmatic-ways\">calculatePizzaArea()<\/code> function (which quite honestly, most of the work was already completed earlier!). <\/p>\n\n\n\n<p>What do we need to calculate the area of a pizza? Our program requirements basically just tell us that the area of a pizza is calculated the same way as the area of a circle, giving us the constant of <code class=\"pragmatic-ways\">PI = 3.14159<\/code>. Then we already got our diameter from the user before, so let&#8217;s move that function in here then convert the diameter into the radius.<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-6\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><div><code lang=\"cpp\" class=\"hljs language-javascript language-cpp\">double calculatePizzaArea() {\n   int pizzaDiameter = getPizzaDiameterFromUser();\n   double pizzaRadius = pizzaDiameter \/ <span class=\"hljs-number\">2<\/span>;\n   <span class=\"hljs-keyword\">return<\/span> calculateCircleArea(pizzaRadius);\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-6\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>The <code class=\"pragmatic-ways\">calculatePizzaArea()<\/code> function now takes care of getting the pizzaDiameter from the user input, then converting that diameter into the radius, then just simply calls a <code class=\"pragmatic-ways\">calculateCircleArea()<\/code> function to return the area of a circle, since that&#8217;s what the area of a pizza is anyways. <\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-7\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><div><code lang=\"cpp\" class=\"hljs language-javascript language-cpp\">double calculateCircleArea(double radius) {\n   <span class=\"hljs-keyword\">const<\/span> double PI = <span class=\"hljs-number\">3.14159<\/span>;\n   <span class=\"hljs-keyword\">return<\/span> PI * pow(radius, <span class=\"hljs-number\">2.0<\/span>);\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-7\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Creating a function specifically for calculating the area of a circle makes our code a lot more flexible than if I just included the area function inside of the <code class=\"pragmatic-ways\">calculatePizzaArea()<\/code> function itself. Now, for whatever reason, if our program elsewhere needs to calculate the area of a circle, it can just use this simple function without needing to get all the details about getting a pizza&#8217;s diameter. <\/p>\n\n\n\n<h4>Calculate the number of pizzas needed<\/h4>\n\n\n\n<p>This calculation should be much simpler. We can now just take the <code class=\"pragmatic-ways\">numberOfSlicesPerPizza<\/code> we calculated above and pass that to a separate function which does the rest of the calculations that we need. <\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-8\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><div><code lang=\"cpp\" class=\"hljs language-javascript language-cpp\">int calcNumPizzasNeeded(double numberOfSlicesPerPizza) {\n   int slicesPerPerson = <span class=\"hljs-number\">3<\/span>;\n   int numberOfPeople = getNumberOfPeopleFromUser();\n <span class=\"hljs-keyword\">return<\/span> ((numberOfPeople * slicesPerPerson) \/ numberOfSlicesPerPizza) + <span class=\"hljs-number\">1<\/span>;\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-8\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Here, we also moved the assumed <code class=\"pragmatic-ways\">slicesPerPerson<\/code> variable directly into this function, since before it used to be unnecessarily defined at the top of the program. <\/p>\n\n\n\n<h3>Extracting the display<\/h3>\n\n\n\n<p>Now we have all our data, we just simply need to display the results. When I originally wrote this assignment, I guess I was trying to be cute and add a little flair and extra unnecessary data to the output. But if we look at our requirements, all we need to do is &#8220;display the number of slices per pizza and the number of pizzas needed for the party&#8221; and then to make sure the &#8220;number of slices should be fixed point and rounded to one decimal place.&#8221; So let&#8217;s just keep it simple this time. <\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-9\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><div><code lang=\"cpp\" class=\"hljs language-javascript language-cpp\"><span class=\"hljs-keyword\">void<\/span> displayResults(double numberOfSlicesPerPizza, int numPizzasNeeded) {\n   cout &lt;&lt; endl;\n   cout &lt;&lt; <span class=\"hljs-string\">\"Number of slices per pizza: \"<\/span>  \n     &lt;&lt; setprecision(<span class=\"hljs-number\">1<\/span>) &lt;&lt; fixed &lt;&lt; showpoint &lt;&lt; numberOfSlicesPerPizza &lt;&lt; endl;\n cout &lt;&lt; <span class=\"hljs-string\">\"Number of pizzas needed: \"<\/span>  \n     &lt;&lt; numPizzasNeeded &lt;&lt; endl &lt;&lt; endl;\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-9\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Now, if we put it all together, our entire program looks like this.<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-cpp\"><\/code><\/pre>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-10\" data-shcb-language-name=\"PHP\" data-shcb-language-slug=\"php\"><div><code lang=\"cpp\" class=\"hljs language-php language-cpp\"><span class=\"hljs-keyword\">include<\/span> \n <span class=\"hljs-keyword\">include<\/span> \n <span class=\"hljs-keyword\">include<\/span> \n using <span class=\"hljs-keyword\">namespace<\/span> <span class=\"hljs-title\">std<\/span>;\n int getUserInput(string message) {\n   int input;\n   cout &lt;&lt; message;   \n   cin &gt;&gt; input;\n   <span class=\"hljs-keyword\">return<\/span> input;\n }\n int getPizzaDiameterFromUser() {\n   <span class=\"hljs-keyword\">return<\/span> getUserInput(<span class=\"hljs-string\">\"What size pizza would you like? (Enter the inch diameter of the pizza)\\n\"<\/span>);\n }\n int getNumberOfPeopleFromUser() {\n   <span class=\"hljs-keyword\">return<\/span> getUserInput(<span class=\"hljs-string\">\"How many people are at the party?\\n\"<\/span>);\n }\n double calculateCircleArea(double radius) {\n   <span class=\"hljs-keyword\">const<\/span> double PI = <span class=\"hljs-number\">3.14159<\/span>;\n   <span class=\"hljs-keyword\">return<\/span> PI * pow(radius, <span class=\"hljs-number\">2.0<\/span>);\n }\n double calculatePizzaArea() {\n   int pizzaDiameter = getPizzaDiameterFromUser();\n   double pizzaRadius = pizzaDiameter \/ <span class=\"hljs-number\">2<\/span>;\n   <span class=\"hljs-keyword\">return<\/span> calculateCircleArea(pizzaRadius);\n }\n double calcNumSlicesPerPizza() {\n   double pizzaArea = calculatePizzaArea();\n   <span class=\"hljs-keyword\">const<\/span> double SLICE_AREA = <span class=\"hljs-number\">14.125<\/span>;  \n   <span class=\"hljs-keyword\">return<\/span> pizzaArea \/ SLICE_AREA;\n }\n int calcNumPizzasNeeded(double numberOfSlicesPerPizza) {\n   int slicesPerPerson = <span class=\"hljs-number\">3<\/span>;\n   int numberOfPeople = getNumberOfPeopleFromUser();\n <span class=\"hljs-keyword\">return<\/span> ((numberOfPeople * slicesPerPerson) \/ numberOfSlicesPerPizza) + <span class=\"hljs-number\">1<\/span>;\n }\n void displayResults(double numberOfSlicesPerPizza, int numPizzasNeeded) {\n   cout &lt;&lt; endl;\n   cout &lt;&lt; <span class=\"hljs-string\">\"Number of slices per pizza: \"<\/span>  \n     &lt;&lt; setprecision(<span class=\"hljs-number\">1<\/span>) &lt;&lt; fixed &lt;&lt; showpoint &lt;&lt; numberOfSlicesPerPizza &lt;&lt; endl;\n cout &lt;&lt; <span class=\"hljs-string\">\"Number of pizzas needed: \"<\/span>  \n     &lt;&lt; numPizzasNeeded &lt;&lt; endl &lt;&lt; endl;\n }\n int main() {\n   double numberOfSlicesPerPizza = calcNumSlicesPerPizza();\n   int numPizzasNeeded = calcNumPizzasNeeded(numberOfSlicesPerPizza);\n displayResults(numberOfSlicesPerPizza, numPizzasNeeded);\n <span class=\"hljs-keyword\">return<\/span> <span class=\"hljs-number\">0<\/span>;\n }<\/code><\/div><small class=\"shcb-language\" id=\"shcb-language-10\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PHP<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">php<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns\">\n<div class=\"wp-block-column\">\n<p><strong>Did you know?<\/strong><\/p>\n\n\n\n<p>Before we wrap up, I want to let you in on a little secret. I wasn&#8217;t born a naturally clean coder. In fact, I used to write pretty ugly code, that is until I picked up this book! If you want to learn how to write clean code, then you NEED to get yourself a copy of the Clean Code book by Robert Martin. <\/p>\n\n\n\n<p>&gt;&gt;&gt; <a href=\"https:\/\/amzn.to\/34kl7DT\" class=\"rank-math-link\">Get your copy of the Clean Code book today!<\/a><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column\">\n<p><a href=\"https:\/\/amzn.to\/34kl7DT\" target=\"_blank\" rel=\"noopener noreferrer\"><\/a><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/amzn.to\/34kl7DT\" target=\"_blank\" rel=\"noopener noreferrer\"><img loading=\"lazy\" width=\"1024\" height=\"769\" src=\"http:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/clean_code_book-1024x769.jpg\" alt=\"\" class=\"wp-image-576\" srcset=\"https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/clean_code_book-1024x769.jpg 1024w, https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/clean_code_book-300x225.jpg 300w, https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/clean_code_book-768x577.jpg 768w, https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/clean_code_book-1536x1154.jpg 1536w, https:\/\/pragmaticways.com\/wp-content\/uploads\/2020\/04\/clean_code_book-2048x1539.jpg 2048w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n\n\n\n<p><\/p>\n<\/div>\n<\/div>\n\n\n\n<h2>Conclusion<\/h2>\n\n\n\n<p>Let&#8217;s recap a few of the high-level details of what we accomplished in this refactoring tutorial. <\/p>\n\n\n\n<ul><li>We extracted lower-level implementation details from the higher-level functions by creating separate functions<\/li><li>We moved variable declarations and initializations closer to where they&#8217;re actually used, thus reducing the need for globally scoped variables at the top of the <code class=\"pragmatic-ways\">main<\/code> function<\/li><li>We renamed some variables, giving them a little bit more explicit description to their intent and meaning<\/li><\/ul>\n\n\n\n<p>If you liked this tutorial and would like to get some feedback on your own assignments, feel free to join our Facebook group and submit your request! Click here to join the <a href=\"https:\/\/www.facebook.com\/groups\/SoftwareEngineeringMastermindGroup\" class=\"rank-math-link\">Software Engineering Mastermind Group<\/a>!<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This is a beginner level tutorial on refactoring some old code I wrote a while ago. If you want to submit a homework assignment for a code review to be<\/p>\n","protected":false},"author":1,"featured_media":567,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[42,33],"tags":[],"_links":{"self":[{"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/posts\/554"}],"collection":[{"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/comments?post=554"}],"version-history":[{"count":0,"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/posts\/554\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/media\/567"}],"wp:attachment":[{"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/media?parent=554"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/categories?post=554"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/tags?post=554"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}