zatchheems.github.io/03-javascript/html/joys-of-javascript.html at master · zatchheems/zatchheems.github.io · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
<!DOCTYPE html>
<html>
  <head>
    <title>Joys of Javascript</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link href="https://fonts.googleapis.com/css?family=Roboto+Slab:400,700,800" rel="stylesheet">
    <link href="https://fonts.googleapis.com/css?family=BioRhyme:400,700,800" rel="stylesheet">
    <link rel='stylesheet' type='text/css' href="../css/reset.css" >
    <link rel='stylesheet' type='text/css' href="../css/theme.css">
    <link rel='stylesheet' type='text/css' href="../css/styles.css" >
    <link rel='stylesheet' type='text/css' href="../css/new-styles.css" >
  </head>
  <body>
    <header>
      <div><pre id='ascii-title' style='line-height:87%;'>
  ____   ___   __ __  _____      ___   _____
 |    | /   \ |  |  |/ ___/     /   \ |     |
 |__  ||     ||  |  (   \_     |     ||   __|
 __|  ||  O  ||  ~  |\__  |    |  O  ||  |_
/  |  ||     ||___, |/  \ |    |     ||   _]
\  `  ||     ||     |\    |    |     ||  |
 \____j \___/ |____/  \___|     \___/ |__|

  ____   ____  __ __   ____  _____   __  ____   ____  ____  ______
 |    | /    ||  |  | /    |/ ___/  /  ]|    \ |    ||    \|      |
 |__  ||  o  ||  |  ||  o  (   \_  /  / |  D  ) |  | |  o  )      |
 __|  ||     ||  |  ||     |\__  |/  /  |    /  |  | |   _/|_|  |_|
/  |  ||  _  ||  :  ||  _  |/  \ /   \_ |    \  |  | |  |    |  |
\  `  ||  |  | \   / |  |  |\    \     ||  .  \ |  | |  |    |  |
 \____j|__|__|  \_/  |__|__| \___|\____||__|\_||____||__|    |__|

</pre></div>
      <h2 class='date'> June 9th, 2018</h2>
    </header>
    <article class='container'>
      <section id="todo" >
        <h1>To Do's:</h1>
        <ul>
          <li>How to Learn Javascript</li>
          <li>What is Javascript?</li>
          <li>The Console</li>
          <li>Alerts, Prompts, Confirms</li>
          <li>Conditionals</li>
          <li>Arrays</li>
        </ul>
      </section>
      <section>
        <h1>How to Learn Javascript</h1>
        <p>For many of you, Javascript will be your first proper programming language.
          For others, some of this will seem familiar if you've ever worked in C/C++, Java
          or Python.
        </p>
        <p>Learning this new language involves:
          <ul>
            <li><span class='bold gray'>Building blocks:</span>
             putting together many small pieces, figuring out how they fit together</li>
            <li><span class='bold gray'>Taking notes</span>: how does <span class='gray'>[thing]</span> work?
              When and why do I use it?</li>
            <li><span class='bold gray'>Keeping organized</span>: keep your HTML in an HTML folder,
              CSS in a CSS folder, etc.
              Projects very quickly become huge and unwieldly. It's incredibly helpful to know
              where everything is. (No organized chaos.)
            </li>
            <li><span class='bold gray'>Hands-on experience</span>: reading code is never a good substitute
              for trying things out on your own. Try re-running coding exercises, not just rereading them.
              You will retain more and for longer that way.
            </li>
          </ul>
        </p>
        <div class="activity">
          <h2>Student activity!</h2>
          <p>With a partner, take a look at the instructions being sent out to you via Slack.
            Download this file and open it in Chrome, observing what happens.
          </p>
          <p>How does the code relate to what you observe in your browser? Talk with your
            partner about this.
          </p>
          <p>Note: We haven't covered JavaScript before, but a big part of being a developer
            is learning on the fly! We won't be going over this example quite yet, there's
          more to come...</p>
        </div>
        </section>
        <section>
          <h1>What exactly
            <span class='italic'>is</span> Javascript?</h1>
          <p>If HTML is the content and CSS is the look and feel, where does Javascript fit in?</p>
          <p>JS is what we use to
            <span class='bold gray'>do things</span>. We can manupulate the browser's DOM (document object model), add new content, change styles, make complex
            animations, fetch and store data, or even make browser games!</p>
          <p>In short:</p>
          <p>HTML &RightArrow; content</p>
          <p>CSS &RightArrow; style</p>
          <p>JS &RightArrow; interactivity</p>
          <h2>Variables</h2>
          <p>Syntax: <span class='property'>var</span>
            <span class='selector'><span class='selector'>myVar</span>
          <span class='special-char'>=</span>
          <cpan class='value'>2</cpan><span class='special-char'>;</span>
          </span></p></p>
          <pre class="brush: javascript">
/* boolean: true/false */
var possibility = true;

/* number */
var number = 42;
var two_pi = 6.28318;

/* string */
var greeting = "what's good?";
var otherGreeting = 'salutations, ya nerd';
          </pre>
          <p>Variables in JS can be: strings of text, numbers, or booleans—there are some more
            data types but we won't cover them quite yet.
            They are like boxes in which we can store information. How we declare them determines
            how we can access them later. (We can just stick with <code>var</code> for now, to make
            things easy.)
          </p>
          <div class='student-activity'>
            <h2>Student activity!</h2>
            <p>We're going to practice variable declaration by tinkering with
              a file.
            </p>
            <ul>
              <li>Fill in the missing Javascript code to create variables.</li>
              <li>When you are finished, open the file in Chrome to check the output.</li>
              <li>If you successfully completed the activity, you should see a series of
                pop-up windows with text inside.</li>
              <li>Finally, look at the rest of the code and try to figure out why the text
                displayed the way it did.</li>
            </ul>
          </div>
        </section>
        <section>
          <h1>The Console</h1>
          <p>Your console is your best friend when it comes to developing and debugging
            Javascript. It's a quick way to execute code on the fly and see what's going on
            in your code.
          </p>
          <div class='activity'>
            <h2>Instructor activity...</h2>
            <p>Let's crack open our dev tools and play with the console! </p>
            <p>We can display some text, look at the contents of variables and make new ones.</p>
          </div>
          <div class='student-activity'>
            <h2>Student activity!</h2>
            <p>Open up the file sent to you and modify the code such that it uses
              <code>console.log()</code> instead of alerts to display messages.
              Discuss with each other the difference between using <code>console.log()</code>
              and <code>alert()</code>.
            </p>
          </div>
        </section>
        <section>
          <h2>Alerts, Prompts, Confirms</h2>
          <div class='activity'>
            <h2>Instructor activity...</h2>
            <p>Let's walk through a file to try to understand the difference between
              these functions. <span class='bold gray'>Functions</span> are expected to
              receive input and return <span class='italic'>something</span>.
              <small>(More on
              functions later.)</small>
            </p>
            <p>Pay close attention to which functions store input and of what type.
              Also pay attention to what each function <span class='bold'>returns</span>.
            </p>
          </div>
          <p>Taking a moment to step back a bit, what's the different between these
            three functions? What do they return?
          </p>
          <div class='student-activity'>
            <h2>Student activity!</h2>
            <p>Write JavaScript code that does the following:
      <li>Using a confirm, ask the user, "Do you like
        <span class='underline'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span>?" Store their response in a variable.</li>
      <li>Using a prompt, ask the user, "What kind of
        <span class='underline'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span> do you like?"
      Store their response in a variable.</li>
      <li>Alert both variables to the screen.</li>
            </p>
          </div>
          <p>Another useful function is <code>document.write()</code>, which allows us
          to write text (or HTML!) directly to the browser (the document). More on that later.</p>
        </section>
        <section>
          <h2>Conditionals</h2>
          <p>An absolutely enormous amount of the code you will be writing will involve
            the use of <span class='bold gray'>conditionals</span>, or statements that only
            execute conditionally. Their structure:
          </p>
          <blockquote>if some condition is met, do something; else, do a different something.</blockquote>
          <p>How does this look like in code?</p>
          <pre class="brush: javascript">
if ( condition ){
  // Do a thing or two or several
}
else {
  // Otherwise do something completely different
}

/* That condition can be anything that returns a boolean: */
a == b;
a !== b;
c > d;
c &lt;= d;
e // e is a boolean
          </pre>
          <p>This concept is <span class='bold'>absolutely critical</span>! You will be
          using it extensively throughout the rest of this course.</p>
          <div class='student-activity'>
            <h2>Student activity!</h2>
            <p>This activity will allow you to practice with conditionals and prompts/confirms.</p>
            <ul>
              <li>Create a website (from scratch) that asks users if they eat steak.</li>

    <li>If they respond with "yes", write the following to the page: "Here’s a Steak Sandwich!"</li>

    <li>If they respond with "no", write the following to the page: "Here’s a Tofu Stir-Fry!"</li>

    <li><span class='bold gray'>Bonus:</span> Ask what the user’s birth year is. If they are under 21, alert the following: "No Sake for you!"</li>

            </ul>
            <small><span class='bold gray'>Hint:</span> You will need to use <code>document.write()</code> from a little while back.</small>
          </div>
          <div class='activity'>
            <h2>Class activity</h2>
            <p>Let's look at a demo file with a set of conditionals and walk through it.
            As we step through it, let's look at some <code>if</code> statements and determine
            if they will execute.</p>
            <p>We'll run the file in our browser to see if it functions how we expected.</p>
          </div>
        </section>
        <section>
          <h1>Arrays</h1>
          <p>Variables can also be <span class='bold gray'>arrays</span>, which are
          collections of other data. You can think of arrays as variables containing
          other variables.</p>
          <p>Syntax for declaring an array:</p>
          <span class='monospace'>
            <span class='property'>var</span>
            <span class='selector'>array</span>
            <span class='special-char'>=</span>
            <span class='special-char'>[</span>
            <cpan class='value'>ham</cpan><span class='special-char'>,</span>
            <cpan class='value'>spam</cpan><span class='special-char'>,</span>
            <cpan class='value'>eggs</cpan>
            <span class='special-char'>]</span><span class='special-char'>;</span>
          </span>
          <hr>
          <p>Syntax for retrieving an element:</p>
          <span class='monospace'>
            <span class='selector'>array</span>
            <span class='special-char'>[</span>
            <cpan class='value'>index</cpan>
            <span class='special-char'>]</span><span class='special-char'>;</span>
          </span>
          <p>Each element in an array has a number,<span class='italic'>
            starting from 0 and ending at length–1</span>.</p>
          <p>Your 0th index element is the first element in the array.</p>
          <p>Which element is this: <span class='selector'>animals</span>
          <span class='special-char'>[</span>
          <cpan class='value'>2</cpan>
          <span class='special-char'>]</span>
          </span> ?</p>
          <pre class="brush: javascript">
var animals = [ 'axolotl', 'emu', 'pangolin', 'ibex' ];

// Whitespace doesn't matter, so this might be neater:

var animals = [
  'axolotl',
  'emu',
  'pangolin',
  'ibex'
];

// We can nest arrays as well:

var odds_evens = [
  [ 0, 2, 4, 6, 8],
  [ 1, 3, 5, 7, 9]
];
          </pre>
          <div class='activity'>
            <h2>Student activity!</h2>
            <p>With a partner, take a few moments to look over the given code. Above each
              <code>console.log()</code> write a comment "predicting" what you think the
              output will be.</p>
            <p><span class='gray bold'>Hint</span>: Comments are the grayed lines that begin with
              <code>//</code> (or <code>/* comment... */</code> like CSS).</p>
            <p>These lines are ignored by JavaScript, and they allow you to explain your code.
              Commenting your code is an extremely useful habit to get into as it
              allows other developers to more easily read your code.
              It will also help you better understand your own applications when
              you look back at them.</p>
          </div>
          <div class="activity">
            <h2>Challenge I</h2>
            <p>Create a website that accomplishes the following:</p>
            <ul>
              <li>Create an array of your favorite bands.</li>
              <li>With a prompt, ask the user's favorite band.</li>
              <li>If it's one of your favorites, alert: "YEAH I LOVE THEM!"</li>
              <li>If it's not, alert: "Nah. They're pretty lame."</li>
            </ul>
      <p><span class='gray bold'>Hint:</span> You will need to research how to use <code>.indexOf()</code>.
        You will also need to research how to use <code>.toLowerCase()</code>.</p>
          </div>
        </section>
    </article>
  </body>
  <!-- Uncomment below to run favBands.js example.
       Output will appear below body becuase script is loaded after content renders. -->
  <!-- <script type='text/javascript' src="../js/favBands.js"></script> -->
  <!-- Script to make <pre> tags pretty -->
  <script type='text/javascript' src="../js/syntaxhighlighter.js"></script>
</html>