You should have knowledge of any of the existing programming languages. Solidity language syntaxes are very similar to Java, JavaScript, and Python syntaxes. A developer who has created projects using Java, JavaScript, or Python can pick up and learn Solidity very easily. You should also have some basic knowledge of OOPS concepts, blockchain, wallets, private key, public key, consensus algorithms, and exchanges.

One very important thing to note here is that, in order to write smart contracts for decentralized applications, you need to have a completely new mindset. Up until now, you have probably been building applications using Java, JS, or another language in which you can fix bugs later on, even in the production environment when something goes wrong. However, smart contracts are immutable. If your contract is deployed in production, you are done. If there is a bug left in the contract, you will be unable to fix it. Hence, you need to ensure that all your smart contracts are well-tested and have no bugs present in them. 

You can download the example code files for this book from your account at www.packt.com. If you purchased this book elsewhere, you can visit www.packt.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packt.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest versions of the following:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Mastering-Blockchain-Programming-with-Solidity. If there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

We provide a PDF file that has color images of the screenshots/diagrams used in this book. You can download it at https://static.packt-cdn.com/downloads/9781839218262_ColorImages.pdf.

To see the code being executed please visit the following link: http://bit.ly/2Yv6kpm.

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "Solidity supports different data types, including uint, int, address, and many more."

A block of code is set as follows:

contract VariableStorage {
   uint storeUint; //uint256 storage variable
    //...
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

contract VariableStorage {
    uint storeUint; //uint256 storage variable
    //...
}

Any command-line input or output is written as follows:

$ npm install -g ganache-cli

Bold: Indicates a new term, an important word, or words that you see on screen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "As mentioned earlier, you can start a local Ganache blockchain instance by just clicking on the QUICKSTART button."