now we've talked about this a little bit already, but if we go ahead, for example, and maybe delete this semicolon, and we go to try to compile, and we scroll down, you'll see we get this error: partial error expected semicolon but got bracket instead, and it gives us this little red exclamation mark on the line that it's having an issue with. All these red errors mean that your code isn't compiling, and you can't actually deploy this to the blockchain because Solidity doesn't know how to turn this human-readable code into machine-readable code. So, we need to add this semicolon here, recompile, so we get no errors. Now, interestingly though, if we go to the top and let's say we delete this SPDX license identifier, and now we compile, we scroll down, we get a yellow box, and it says warning instead of error. It says warning: spdx license identifier not provided source file blah blah blah. Interestingly though, if we compile this, we actually, let's delete our last simple storage, we can deploy this. So, if something

important to note is warnings are just that. They're just warnings. They won't prevent you from deploying or compiling your code. Errors will prevent you from deploying or compiling your code. Now, even with that being said, though, it is good to try to remove all of the warnings because the warnings are generally there for a reason. They're warning you that you might be doing something bad, and sometimes if you have a bug in your code, simply just listening to the warnings would have solved it. So, it's best to listen to the warnings here. So, to summarize, if it's red, it's broken. If it's yellow, you might want to check it out. Additionally, when it comes to these errors and these warnings, this is where using our AI and Google searching skills can really come in handy. Let's say, for example, I ran our code, I get this error, I read the error, and I don't really understand what's going on here. What we can do is we could maybe copy this error and use any of these search features that we talked about, resources.

for this course, we can use ChatGPT or find GitHub discussions, Stack Exchange, Ethereum, and Puranum, and I'll explain what each one of these is good for later in the course. But for example, let's go and try out Find. Find is an AI search engine for developers. What it does is it first does a Google search, and then it reads all those links, and based off the links it reads, it tries to give you an answer. So, what we could do is we could say, I am getting this compiler error in Solidity. How do I fix it? We hit this little drop-down, put any code or context here, we'll paste our error. This is the error like this, and we'll go ahead and hit search. We get a pretty verbose response on what's going on with our code. We could actually take this a step further, and we could copy our entire code base, and we could paste it under here. We say code. I usually put three backticks before and after any code that I use, and I'll teach you why in the future. Well, let's

Go ahead and hit enter and research it. Actually, it is able to read our code and say one way to fix the error is to simply add a semicolon at the end of the line where you push the new person to the dynamic array list of people. And we could see if we do indeed get a way to just copy our add person function. And we can scroll down and just paste it on top with it being fixed. And we could also say concise because it's being a little too verbose for us. We'll hit enter again and it wasn't that concise. But a lot of these AI tools, like I said, are still in beta. But this was a good example of how using an AI tool like this can actually help you detect bugs. Like I said, oftentimes they will still get things wrong, which is why it's important for you to know about GitHub discussions, Stack Exchange, Piranha, etc. Later in the course, I'll explain more about how to ask good questions, how to do good AI prompting, how to format your questions.

and how to search and learn more. One of the key pieces of being a really good software engineer or a good prompt engineer is less about actually knowing the information and more about knowing where to find the information. So, throughout this course, I want you to practice using these resources because they're going to help you be a much stronger developer, much stronger prompt engineer, and just be better at everything that we're going to go over in this course. If Find or Chat should be T gives you a poor answer, be sure to use the GitHub discussions. If you have a question specific to this course, be sure to use the GitHub discussions, or if you have a more general question about Solidity, about Foundry, or anything like that, you can use one of these resources. Again, I'll go over this more later, but great job! You've done your first bit of prompt engineering. Congratulations!

Lesson 2 Part 6 | Errors & Warnings - Solidity & Foundry Full Course

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