mirror of
https://github.com/Brandon-Rozek/website.git
synced 2024-11-24 17:16:30 -05:00
190 lines
6.6 KiB
HTML
190 lines
6.6 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">
|
|
<h2>Counting Loop</h2>
|
|
<p>Looking at the following example code</p>
|
|
<pre><code class="language-java">int i;
|
|
for (i = 0; i < 3; i++) { //begin for
|
|
System.out.println("i = " + i); //body
|
|
} //end for
|
|
System.out.println("After loop, i = " + i);</code></pre>
|
|
<p><code>i = 0</code> is the initializing statement</p>
|
|
<p><code>i < 3</code> is the conditional, that is when the loop ends</p>
|
|
<p><code>i++</code> is the increment/decrement</p>
|
|
<p><code>i++</code> is synonymous with <code>i = i + 1</code></p>
|
|
<p>The initialization statement only occurs once at the beginning of the loop. </p>
|
|
<h3>Execution Example</h3>
|
|
<p>Let us go through this for loop example</p>
|
|
<ul>
|
|
<li>Let us set <code>i = 0</code></li>
|
|
<li>Is <code>i < 3</code>? Yes execute the body
|
|
<ul>
|
|
<li>The body executes an output of <code>"i = 0"</code></li>
|
|
</ul></li>
|
|
<li>Now we increment <code>i ++</code>, i is now 1</li>
|
|
<li>Is <code>i < 3</code>? Yes, 1 is less than 3. Execute body
|
|
<ul>
|
|
<li>The computer prints out <code>"i = 1"</code></li>
|
|
</ul></li>
|
|
<li>Increment <code>i++</code> i is now 2</li>
|
|
<li>Is <code>i < 3</code>? Yes 2 is less than 3. Execute body
|
|
<ul>
|
|
<li>The computer prints out <code>"i = 2"</code></li>
|
|
</ul></li>
|
|
<li>Increment <code>i++</code>, i is now 3</li>
|
|
<li>Is <code>i < 3</code>? No 3 is not less than 3
|
|
<ul>
|
|
<li>Don't execute body of loop</li>
|
|
</ul></li>
|
|
</ul>
|
|
<p>Exit loop. Print <code>"After loop, i = 3"</code></p>
|
|
<h3>Condensing Syntax</h3>
|
|
<p>You can also do the declaration in the initialization statement</p>
|
|
<pre><code class="language-java">for (int i = 0; i < 3; i++) {
|
|
System.out.println("i = " + i);
|
|
}</code></pre>
|
|
<p>This now runs like above without the <code>"After loop, i = 3"</code> print. You cannot access the variable <code>i</code> outside the for loop since in this example, it belongs to the for loop's scope.</p>
|
|
<h2>Logic Expressions</h2>
|
|
<h3>And Statements</h3>
|
|
<p>With the AND operator <code>&&</code> both the left and right side needs to be true for the expression to be true.</p>
|
|
<pre><code class="language-java">true && true // true
|
|
true && false // false
|
|
false && true // false
|
|
false && false // false</code></pre>
|
|
<h3>Or Statements</h3>
|
|
<p>With the OR operator <code>||</code> either the left or right side needs to be true for the expression to be true.</p>
|
|
<pre><code class="language-java">true || true // true
|
|
true || false // true
|
|
false || true // true
|
|
false || false // false</code></pre>
|
|
<h3>Examples</h3>
|
|
<p><strong>Example</strong>: Print out the number <code>n</code> if it is between 10 and 20 (inclusive)</p>
|
|
<pre><code class="language-java">if (n >= 10 && n <= 20) {
|
|
System.out.println(n);
|
|
}</code></pre>
|
|
<p><strong>Example</strong>: Print out the <code>age</code> if it is not of young adult age. Young adult range is from 18 to 39 (inclusive)</p>
|
|
<pre><code class="language-java">if (!(age >= 18 && age <= 39)) {
|
|
System.out.println(age);
|
|
}</code></pre>
|
|
<p>Or you can use De Morgan's Law (for the curious)</p>
|
|
<pre><code class="language-java">if (age < 18 || age > 39) {
|
|
System.out.println(age);
|
|
}</code></pre>
|
|
<h2>For Loops (Cont.)</h2>
|
|
<h3>Backwards counting</h3>
|
|
<p>You can use the loop to count backwards</p>
|
|
<pre><code class="language-java">for (int i = 10; i > -1; i--) {
|
|
System.out.println(i);
|
|
}</code></pre>
|
|
<p>This prints the following</p>
|
|
<pre><code class="language-java">10
|
|
9
|
|
8
|
|
7
|
|
6
|
|
5
|
|
4
|
|
3
|
|
2
|
|
0</code></pre>
|
|
<h3>Rows-Columns</h3>
|
|
<p>You can make rows and columns of asterisks</p>
|
|
<pre><code class="language-java">for (int j = 0; j < someNumber; j++) { // Corresponds to rows
|
|
for (int i = 0; i < someNumber2; i++) { // Corresponds to columns
|
|
System.out.print("*");
|
|
}
|
|
System.out.println(""); // Goes to the next row
|
|
}</code></pre>
|
|
<p>If <code>someNumber</code> equals <code>someNumber2</code>, then we have the same amount of rows as columns.</p>
|
|
<p>Let <code>someNumber</code> equal to 2 and <code>someNumber2</code> equal to 2</p>
|
|
<p>Output:</p>
|
|
<pre><code>**
|
|
**</code></pre>
|
|
<h3>Right Triangles</h3>
|
|
<p>You can make a right triangle of Tilda with the following code</p>
|
|
<pre><code class="language-java">for (int i = 1; i <= num; i++) { // Corresponds to the row
|
|
for (int j = 0; j < i; j++) { // Corresponds to the column and stops at the current row number
|
|
System.out.print("~");
|
|
}
|
|
System.out.println(""); // Moves to next row
|
|
}</code></pre>
|
|
<h5>What are for-loops used for? <em>Reusing code</em></h5>
|
|
</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>
|