Heads up! To view this whole video, sign in with your Courses account or enroll in your free 7-day trial. Sign In Enroll
Well done!
You have completed Java Basics!
You have completed Java Basics!
Preview
In this video, we will learn how to check multiple conditions in one statement using a logical OR statement.
Additional Reading
- Operator summary
- Example of an extreme cat lover to use for your logical comparisons.
Related Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign upRelated Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign up
Now that we know how to block
on a single specific word.
0:00
Let's expand our reach, and
block more than just one offensive word.
0:03
Now one trait that we have at our
disposal, is that we can check
0:07
multiple conditions by using what is
known as a logical or expression.
0:09
Which means we can do something like this,
if the noun is dork, or
0:14
the noun is jerk, exit the application.
0:19
In fact you could chain these or
statements on forever.
0:22
Let's go introduce a logical OR
0:26
into your application to block the user
from entering either dork or jerk.
0:28
Blocking against the word jerk in
our code is actually pretty easy.
0:34
In fact the only thing I think I need to
show you is what OR syntax looks like.
0:37
So let's go to our IF statement when
we were checking for dork in the past.
0:41
Let's add an OR statement in here, so
we're gonna do a double pipe symbol.
0:45
Pipe is above the enter key.
0:50
That's what OR looks like so
it's gonna say noun
0:53
equals ignore case or
noun equals lowercase on jerk.
0:58
Great.
1:05
Now this line is getting a little bit long
and in fact if we added one more OR on
1:06
here probably go off the screen and then
somebody might not see that it's there.
1:10
So one way that we can do to battle
that is because we're inside of this
1:13
parenthesis here.
1:16
We can add a new line and
take advantage of that space.
1:18
So now looks much better.
1:22
While we were writing that, one thing that
you might have thought was that you could
1:25
do the same thing with two if statements,
right?
1:28
You could write this if statement here
you could say equalsIgnore "dork" or
1:30
you can make another one that
says if noun.equalsIgnore "jerk".
1:35
But what would happen then is that you'd
be writing these same lines inside of
1:39
these, this code block here,
you'd be writing that same code twice.
1:42
And that's never a good idea.
1:45
All right so let's give this a go.
1:47
I'm gonna save it and
then I'm gonna compile and run.
1:48
I'll say 20.
1:55
And we will do big and we're gonna put
in jerk here, great, we caught it.
1:58
So let's walk that really quick.
2:04
So what we've done here is we have this
first line that's gonna come in here.
2:06
It's gonna say noun, and we put in, jerk.
2:09
So noun is gonna be jerk.
2:11
And it says, if noun equals dork,
and that's a false.
2:12
So that's going to say false.
2:15
So, false or true.
2:16
Right, because noun equals jerk and
it does so we're going to say false or
2:20
true and if you imagine that
anytime there's a true in there.
2:23
It's gonna be true.
2:27
Okay, so
let's make sure that the dork still works.
2:28
Awesome it does after using this a bit,
2:37
I think we need to do something
different about that exit.
2:39
It would be good to give the user
a second chance to enter a nicer word.
2:42
Let's see if we can't fix
that in the next lesson.
2:46
And one more thing I wanted
to show if you wanted to do
2:48
another one of these you can always
chain them with another one.
2:51
So right?
So if we wanted to say.
2:53
Another guy here, say nerd.
2:57
All right perfect and
that is how Ors work.
3:02
Great we just learned one way that we
could check multiple conditions in one
3:08
IF statement.
3:12
By not making two identical code
blocks we avoided repeating ourselves.
3:14
A goal of programming is to make sure
that you don't repeat yourself or
3:18
often referred to as DRY.
3:22
As you advanced through your learnings,
you'll hear this phrase often and I'm sure
3:24
it will be hammered into your thinking
as you begin coding bigger applications.
3:28
What were you thinking about logic?
3:32
I'd like to also introduce you
to ORs counterpart which is AND.
3:34
Well OR
returns true if any statement is true and
3:38
will only return true if
all expressions are true.
3:42
Logical and
use the double ampersand simple
3:46
as this logic is such an important
concept and used all over the place.
3:50
Let's go back and
review our dating site analogy.
3:54
So an example of an OR
statement is must love cats or dogs.
3:57
A cat lover would be tested and
she'd say, do you love cats?
4:01
And she'd say gee, yes,
yes, yes, yes, yes.
4:04
No need to ask about dogs as this
person definitely met the requirement.
4:07
Now let's look at another example.
4:11
The request is younger than 40 and
has no children and loves art.
4:13
This elderly gentleman has
prompted how old he is.
4:18
And there is no need to go on asking any
further questions as he doesn't meet
4:21
all the conditions.
4:25
Okay, so
4:26
let's take a really quick exercise
around the statements before we move on.
4:27
You need to sign up for Treehouse in order to download course files.
Sign upYou need to sign up for Treehouse in order to set up Workspace
Sign up