website/static/~brozek/index.html?labaide%2Fspring2018%2Fcpsc220%2Fmar29.html

115 lines
3.9 KiB
HTML
Raw Normal View History

2020-01-15 23:07:02 -05:00
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="author" content="Fredrik Danielsson, http://lostkeys.se">
<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 March 29th</h1>
<h2>Enumerated Types</h2>
<p>These represent a fixed set of constants and include all possible values within them.</p>
<p>Let's look at coins. On a daily basis in the US, we use the following coins:</p>
<ul>
<li>Penny</li>
<li>Nickel</li>
<li>Dime</li>
<li>Quarter</li>
</ul>
<p>Other examples include the days of the week, clothes sizes, etc.</p>
<h2>Enum Syntax</h2>
<p>Let's define an <code>enum</code> type</p>
<pre><code class="language-java">public enum Coin { PENNY, NICKEL, DIME, QUARTER}</code></pre>
<p>Now declare and initialize a variable</p>
<pre><code class="language-java">Coin myCoin = Coin.PENNY</code></pre>
<h2>Arrays vs ArrayList</h2>
<p>Arrays require you to say upfront, how many slots you need. ArrayLists are more flexible since you can change the length of the array during Runtime. </p>
<p>Arrays can store objects and primitives such as <code>int</code>, <code>char</code>, <code>boolean</code>, etc.</p>
<p>ArrayLists can only store objects.</p>
<h3>How to declare an ArrayList</h3>
<pre><code class="language-java">ArrayList&lt;objectType&gt; list = new ArrayList&lt;objectType&gt;();</code></pre>
<h3>Differences between getting the length of the array</h3>
<p><strong>Array</strong></p>
<pre><code class="language-java">int length = array.length;</code></pre>
<p><strong>ArrayList</strong></p>
<pre><code class="language-java">int length = array.size();</code></pre>
<h2>For Each Loop</h2>
<p>This is a special loop in where you tell it to go through all the elements of the array, without specifying an index.</p>
<pre><code class="language-java">for (String b : buildings) {
System.out.print(b);
}</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>