I've got some really bad news for you, you aren't perfect.

None of us are.

You're gonna make mistakes.

In fact, I'm still constantly making mistakes.

There are gonna be errors in your code.

There are going to be lots of errors in your code.

In fact, [LAUGH] any time you watch someone coding and

are impressed by their lack of mistakes,

is almost certainly because they spent a lot of time making mistakes and they've

learned to avoid the common pitfalls that we all, as developers, fall into.

The sooner you can view mistakes and

errors as a positive result of your own experimentation, the quicker you will be

on the road to mastering a language and with much less frustration.

Remember, if you aren't failing, you aren't learning.

There are different types of errors.

The most common errors are syntax errors and

they can be very frustrating as you're first diving into a language.

The good news is that Java compiler is very good at reporting these,

and usually, the answer is pretty clear.

Now, let's go break stuff.

Hopefully, you haven't had any errors yet.

Let's intentionally make one.

I'm gonna misspell the string declaration here,

making it spelled as the popular singer, Sting.

Let's see what happens.

Now press the up arrow and get our information back here.

And we will see here that we got an error that says, cannot find symbol.

And if you look, this shows the line number which is 13, line 13,

and it says the error, cannot find symbol.

And then also underneath here there's an arrow that's pointing up exactly where

the problem is.

So that is wonderful, but now you saw me make the change from string, but

if you didn't and if for some reason you didn't see the obvious arrow pointing

at the lead singer of the Police, one place we could turn is the Internet.

Java's been around for a long time.

It'll be hard to stump Google with a Java problem.

It's heard them all.

Let's give it a spin.

I'm gonna copy this, cannot find symbol error,

then I'm gonna swing over to Google and I'm gonna paste that.

So we got some results here, we have 482,000 results.

Let's go ahead and look at the first one here.

I'm feeling lucky.

Okay, when a Java program is being compiled,

the compiler creates a list of identifiers to use.

If it can't find what an identifier refers to, it can't complete the compilation.

This is what we're seeing, this is what the cannot

find symbol error message is saying, that's what we're getting, so it doesn't

have enough information to piece together what the Java code wants to execute.

Okay, so some possible causes, trying to use a variable without declaring it.

Well, that's not the case cuz that our declaration line.

Misspelling a class or method name, possible that we misspelled.

Let's go back and take a, that's right, we did misspell it.

So let's go ahead and put an r back in there.

Okay, so there's an example of a cannot find symbol.

Another one that is very common is this,

if we make this a lowercase s here on the String, then we'll save this.

Let's go ahead and I'll run it again.

Okay, we get a cannot find symbol in its own string, a string is spelled right, so

let's go ahead let's jump back over there.

Let's search for that specifically.

So we have cannot find symbol in string.

Okay, so 998,000 results here.

I scroll down and I see, well, this one's from Oracle.

That's great cuz Oracle's the company that currently makes Java so

let's take a look and see what they have to say here.

This person is having a similar problem that we are.

Java file's not recognizing string as in private string name.

What is going on and could this be an install problem?

Capital letter S.

Everything in Java's case sensitive, okay, great.

So let's go back and we can fix that.

Perfect.

So that's an example of what you can do when you get an error.

Remember, just go out and search for it, come to the forums if you need to as well.

So now we know that we will make syntax errors and what they'll look like.

I'll show off some more common gotchas in logic and

other runtime errors as we dig a little deeper into our program.

I've pointed out the seemingly endless resources on the Internet, but

I want to encourage you once again to use the treehouse community to your advantage.

Your fellow classmates are here to help and by sharing your errors,

it actually gives someone else the ability to learn from your mistakes.