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When we create a project,
Android Studio creates all the files and

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folders that we need behind the scenes.

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Let's run the project to verify
that everything's working.

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We'll also see where to look for

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information about errors if
we run into any problems.

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We'll talk about all these different views
in Android Studio in a little bit, but

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first let's try to run the app.

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There's a couple ways we can do it.

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We can select Run, from the menu up here,
and then choose, Run 'app'.

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Or from the toolbar,
we can click on the Run app button.

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I'll choose this option.

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Also, if you like keyboard shortcuts,
you can hit Shift+F10 on Windows, or

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Ctrl+R on Mac.

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Now we see the device user dialogue.

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If we had an Android phone or tablet
plugged into our computer with a USB

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cable, then it might show up
here as a connected device.

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We'll see how to do that later on.

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But for now we want to launch the emulator
with the default virtual device.

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If your installation doesn't have
a default version virtual device or

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you would like to learn how to create and
customize your virtual devices,

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check out the workshop linked
in the teacher's notes below.

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Once we have selected a virtual device,
we can hit OK.

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Android Studio will launch
the emulator and run our app.

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The emulator may take a little
bit to load, so be patient.

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The good news is that
once the emulator is up,

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we can leave it running to avoid
the wait on subsequent runs.

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In the mean time,
notice down at the bottom,

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there's a message about a Gradle build.

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Gradle is the name of something
that's called a build system.

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And it's responsible for transforming
all the raw materials for the app

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here in Android Studio Into something
that can be installed on the device.

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And there it is.

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You've just ran your first Android app.

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But what if it isn't working?

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How do we know if something went wrong?

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Back in Android Studio, let's click on
Logcat at the bottom of the screen.

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Logcat is Android's logging system.

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It gives us a way to read the system logs,

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which is really useful
when debugging an app.

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If there's anything wrong with your code,

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then the problem might show up here
as some kind of error message.

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Now if we click over to messages, this
shows messages from the build process.

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If anything went wrong when
building your project,

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the error should be reported here.

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And if you do have errors here or
in Logcat and you don't know what to do,

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first search for the error to see if
someone else has already solved it.

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If no one has, then copy the error and
paste it as a question in the community.

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Also, if you've got an idea about which
piece of code is causing the error,

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please include the code
in your post as well.

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Someone who's reading your post can
usually help you a lot faster if they can

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see the code.

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All right,

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now let's break something to see
an example of what an error can look like.

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Let's say I missed a semi-colon.

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If I try to run the app,
then I should get a Gradle build error.

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Sure enough, it says Error: expected.

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And if we double click on the error,

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it will take us to
the appropriate spot in the file.

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And this is a Gradle build error because
it prevents our project from being built.

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Also, we see lots of red squiggly lines
letting us know that we've made an error.

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Let's put the semicolon back and
check to make sure the error is fixed.

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But instead of running the app, let's
click this hammer to build the project.

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And this time, we don't see any errors
which means it was a successful build.

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Another way we can build a project
is to use the Build menu and

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then select Make Project.

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Or if you really want to start a build
from scratch, you can chose clean project,

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which cleans up all the behind the scenes
files, and rebuilds the project for us.

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One last thing, don't be alarmed if
you can't find an error message again.

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You can always find them down
here in messages or Logcat.

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Even if those tabs are missing, you can
still find them by placing your mouse over

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this little square in the corner and
then picking the view you'd like to open.

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Also, clicking the square
will toggle showing and

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hiding these views around the edge.

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And remember, if you're having
any trouble with this stuff,

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head on over to the community and
we'll make sure to help you out.

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We just created and
ran our first Android app.

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Not bad for a few minutes of work.

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We've set up an integrated development
environment or IDE which in our case is

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Android Studio and we saw how
to create and run a new project.

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Coming up, we'll make some
changes to the screen layout and

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then we'll write some actual code.

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Now, everything should be
working at this point,

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which is actually a really
big accomplishment.

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Setting up a computer for

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Android development is a lot
easier than it used to be.

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But things can still go wrong.

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Remember, if you have any problems,
check the community for help.