mirror of
https://github.com/Brandon-Rozek/website.git
synced 2024-11-21 15:56:29 -05:00
169 lines
5.2 KiB
HTML
169 lines
5.2 KiB
HTML
<!DOCTYPE html>
|
|
<html>
|
|
<head>
|
|
<meta charset="utf-8" />
|
|
<meta name="author" content="Brandon Rozek">
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
<meta name="robots" content="noindex" />
|
|
<title>Brandon Rozek</title>
|
|
<link rel="stylesheet" href="themes/bitsandpieces/styles/main.css" type="text/css" />
|
|
<link rel="stylesheet" href="themes/bitsandpieces/styles/highlightjs-github.css" type="text/css" />
|
|
</head>
|
|
<body>
|
|
|
|
<aside class="main-nav">
|
|
<nav>
|
|
<ul>
|
|
<li class="menuitem ">
|
|
<a href="index.html%3Findex.html" data-shortcut="">
|
|
Home
|
|
</a>
|
|
</li>
|
|
<li class="menuitem ">
|
|
<a href="index.html%3Fcourses.html" data-shortcut="">
|
|
Courses
|
|
</a>
|
|
</li>
|
|
<li class="menuitem ">
|
|
<a href="index.html%3Flabaide.html" data-shortcut="">
|
|
Lab Aide
|
|
</a>
|
|
</li>
|
|
<li class="menuitem ">
|
|
<a href="index.html%3Fpresentations.html" data-shortcut="">
|
|
Presentations
|
|
</a>
|
|
</li>
|
|
<li class="menuitem ">
|
|
<a href="index.html%3Fresearch.html" data-shortcut="">
|
|
Research
|
|
</a>
|
|
</li>
|
|
<li class="menuitem ">
|
|
<a href="index.html%3Ftranscript.html" data-shortcut="">
|
|
Transcript
|
|
</a>
|
|
</li>
|
|
</ul>
|
|
</nav>
|
|
</aside>
|
|
<main class="main-content">
|
|
<article class="article">
|
|
<h1>Lecture for January 23</h1>
|
|
<h2>Java Class</h2>
|
|
<p>In Java, your code must live in a class.</p>
|
|
<pre><code class="language-java">public class NameOfClass {
|
|
public static void main(String[] args) {
|
|
// All program code
|
|
}
|
|
}</code></pre>
|
|
<p>It is important that <code>NameOfClass</code> is named meaningfully for the code. It is convention to use CamelCase when using classes. (Capitalize your class names!)</p>
|
|
<p>All methods have a method signature, it is unique to it. For main it is the words <code>public static void</code> and the argument <code>String[] args</code>.</p>
|
|
<p><code>public</code> means that any other piece of code can reference it.</p>
|
|
<p><code>void</code> means that the method returns nothing</p>
|
|
<p><code>main</code> is the name of the method. It is important to have <code>main</code> since that tells the Java Interpreter where to start in your program.</p>
|
|
<p><code>String[] args</code> is the command line arguments inputted into the program. For this part of the class, we don't need to worry about it.</p>
|
|
<p>If you noticed <code>String</code> is a class, it is not a primitive type. This is denoted in Java by having it capitalized.</p>
|
|
<h2>Arithmetic Expressions</h2>
|
|
<p>There is an order of operations in programming as well. It goes like this:</p>
|
|
<ol>
|
|
<li>Parenthesis</li>
|
|
<li>Unary Operations</li>
|
|
<li>*, /, %</li>
|
|
<li>+, -</li>
|
|
</ol>
|
|
<p>And from there you read from left to right.</p>
|
|
<h2>Constant Variables</h2>
|
|
<p>These are variables that can never be changed</p>
|
|
<pre><code class="language-java">final int MINUTES_PER_HOUR = 60</code></pre>
|
|
<p>The keyword <code>final</code> indicates to the Java compiler that it is a constant variable.</p>
|
|
<p>By convention, constants are in all caps with underscores being separated between the words</p>
|
|
<h2>Java Math Library</h2>
|
|
<p>There are some arithmetic expressions that we want to be able to do and we cannot achieve that simply with the standard operations</p>
|
|
<table>
|
|
<thead>
|
|
<tr>
|
|
<th>Method</th>
|
|
<th>Description</th>
|
|
</tr>
|
|
</thead>
|
|
<tbody>
|
|
<tr>
|
|
<td>Math.sqrt(x)</td>
|
|
<td>square root</td>
|
|
</tr>
|
|
<tr>
|
|
<td>Math.abs(x)</td>
|
|
<td>absolute value</td>
|
|
</tr>
|
|
<tr>
|
|
<td>Math.pow(a, b)</td>
|
|
<td>exponentiation $a^b$</td>
|
|
</tr>
|
|
<tr>
|
|
<td>Math.max(a, b)</td>
|
|
<td>returns the maximum of a or b</td>
|
|
</tr>
|
|
<tr>
|
|
<td>Math.min(a, b)</td>
|
|
<td>returns the minimum of a or b</td>
|
|
</tr>
|
|
<tr>
|
|
<td>Math.round(x)</td>
|
|
<td>rounds to the nearest integer</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<h2>Example: Finding Areas</h2>
|
|
<pre><code class="language-java">public class MoreVariables
|
|
public static void main(String[] args) {
|
|
// Decrate a variable
|
|
int x;
|
|
|
|
// Initialize ia variable
|
|
x = 5;
|
|
|
|
// Area of a square
|
|
int squareArea = x * x;
|
|
System.out.println("Area of a square: " + squareArea);
|
|
double newSquare = Math.pow(x, 2);
|
|
System.out.println("Area of square: " + newSquare);
|
|
|
|
// Area of Circle
|
|
final double PI = 3.14159;
|
|
double radius = 3;
|
|
double circleArea = radius * radius * PI;
|
|
System.out.println("Area of circle: " + circleArea);
|
|
|
|
}</code></pre>
|
|
</article>
|
|
</main>
|
|
|
|
<script src="themes/bitsandpieces/scripts/highlight.js"></script>
|
|
<script src="themes/bitsandpieces/scripts/mousetrap.min.js"></script>
|
|
<script type="text/x-mathjax-config">
|
|
MathJax.Hub.Config({
|
|
tex2jax: {
|
|
inlineMath: [ ['$','$'], ["\\(","\\)"] ],
|
|
processEscapes: true
|
|
}
|
|
});
|
|
</script>
|
|
|
|
<script type="text/javascript"
|
|
src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML">
|
|
</script>
|
|
<script>
|
|
hljs.initHighlightingOnLoad();
|
|
|
|
document.querySelectorAll('.menuitem a').forEach(function(el) {
|
|
if (el.getAttribute('data-shortcut').length > 0) {
|
|
Mousetrap.bind(el.getAttribute('data-shortcut'), function() {
|
|
location.assign(el.getAttribute('href'));
|
|
});
|
|
}
|
|
});
|
|
</script>
|
|
|
|
</body>
|
|
</html>
|