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In this video, we will block a specific word from being used in our application.
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All right, so let's block some words
from being allowed to be used.
0:00
As a user of the Internet,
I am sure you've seen
0:04
how not nice humanity can be
when hiding behind a keyboard.
0:06
Let's do our part in attempting
to block this from happening.
0:10
We'll take a few simplistic
approaches to the problem.
0:13
But I'm gonna use these approaches to
introduce you to a few more commonly used
0:15
tools in your Java toolbox.
0:19
First, let's just block the word
dork from being used as our noun.
0:22
We'll start with the same if and
0:26
then exit pattern that we followed
blocking out our underaged users.
0:28
We've already seen how methods can be
called on objects, like console, system,
0:32
and integer.
0:36
Now, here's something that might strike
you as a little strange at first.
0:37
The strings that we've gotten back
from our users, they are objects too.
0:40
And just like console, system, and
integer, they also have methods.
0:44
Let's pop over the official
documentation and
0:49
take a quick peek at what methods
are available to strings.
0:51
I'll just do a quick search here for,
java String.
0:54
And the fist result here,
is from the official Oracle documentation.
0:57
And it's for the Java platform SE,
which is Standard Edition 7.
1:01
We're currently running 8 in WorkSpaces,
but
1:05
the thing that we're gonna look for
has been around forever.
1:08
So let's just go in here.
1:10
And we can scroll down here in this
documentation, very long documentation.
1:13
And there's some bunch of ways
that you can construct the string.
1:19
Here's the methods that are available.
1:22
Let's scroll down a bit here.
1:24
Again, what we're looking for
1:26
is we're gonna see if noun is
actually equal to dork, all right?
1:27
Cuz we wanna try to block that.
1:31
So, is there anything
in here about equals?
1:32
Here's something right here,
1:35
equals compares the string
to the specified object.
1:36
That sounds perfect.
1:39
And it returns a boolean,
which remember, is true or false.
1:40
And that's what we wanna kinda
use in our IF statement.
1:42
So let's open that up.
1:45
Let's take a look.
1:45
So this is equals, and
it returns a boolean.
1:47
And it compares the string to
the specified object that sounds perfect.
1:51
Let's give that a go.
1:54
So we'll go right here
after we have the noun.
1:57
And we'll do another if statement.
2:00
So we're gonna say, if, and
then we're gonna say the noun dot,
2:02
cuz has methods, equals("dork").
2:09
Okay, so that's our statement,
cuz that's gonna return a boolean.
2:17
And that will be be true
if they've typed dork.
2:20
And we'll open up our code block.
2:22
We'll say, write out of the screen,
2:24
That language is not allowed.
2:30
Exiting.
2:34
And we'll exit the program
using that System.exit.
2:42
And we'll pass in 0.
2:45
So we expected that.
2:47
And we'll close the parentheses here.
2:48
Okay, so I'm gonna save.
2:50
And I'm gonna run and compile.
2:53
I'm 20.
2:57
I wish.
2:59
My name's Craig.
3:01
And what they wrote was big and dork.
3:03
That language is not allowed.
3:08
Exiting.
3:09
Awesome it worked, we’re blocked.
3:10
When I was looking at the documentation,
3:14
I noticed that there is
also a See Also section.
3:15
Let's go and and just check out and
ensure that we got the right one.
3:18
The See Also, comparedTo,
and ooh, equals ignore case.
3:23
And case there is talking
about letter case.
3:27
So an upper case a or lower case a.
3:30
Sounds like exactly what we want.
3:33
Let's see that.
3:34
Compares a string to another string
ignoring case considerations, perfect.
3:35
Case strings are considered equal ignoring
case if they are the same length.
3:39
Perfect, let's do that,
cuz that way if somebody yelled,
3:43
DORK in all uppercase letters,
it would get past our censoring code.
3:47
And I don't want that to happen.
3:51
So, let's go ahead and
let's switch to that method.
3:51
So we'll say, equalsIgnoreCase.
3:55
Save, and let's go and compile again.
3:58
Again, big.
4:07
And then let's try to break it.
4:08
We'll say DoRk.
4:09
Awesome, great job.
4:13
We stopped the haters.
4:15
Excellent job!
4:17
No one's gonna call me a dork now, but,
well, at least not on our program.
4:18
I'm glad you got a chance to get slightly
familiar with the documentation.
4:23
It can definitely be a bit verbose, but
you shouldn't let that overwhelm you.
4:26
Remember, much like after a few
weeks of learning Spanish,
4:30
you shouldn't expect to be able to open
the Spanish textbook to Chapter 15 and
4:33
understand all that information.
4:36
But what you should feel good
about is that some of those words
4:39
are now starting to make sense, you've
learned a lot and you're doing great.
4:42
We'll expand our approach
to the next video.
4:46
But first, let's test out those new
string methods we just learned.
4:48
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