Beginner's Guide: Solidity for Blockchain Development
Written by  Daisie Team
Published on 10 min read

Contents

  1. What is Solidity?
  2. Why use Solidity in Blockchain development?
  3. Basic syntax of Solidity
  4. How to set up Solidity environment
  5. Writing your first Smart Contract
  6. Variables and Data Types
  7. Functions in Solidity
  8. Control Structures in Solidity
  9. Error Handling in Solidity
  10. Best practices for Solidity development

If you've been thinking, "Should I start learning Solidity for blockchain development?" then you're at the right place! This guide will give you a good understanding of the basics and get you started on your journey. So, let's dive in and start understanding what makes Solidity an excellent choice for blockchain development.

What is Solidity?

Solidity is a programming language, specifically designed for creating and implementing smart contracts on Ethereum and other blockchain platforms. Its syntax is similar to JavaScript, which makes it easier to pick up if you're already familiar with coding.

Now, you might be wondering, "What does a smart contract do?" Well, smart contracts are self-executing contracts with the terms of the agreement directly written into code. So, if you're trying to create a blockchain application—say, a cryptocurrency like Bitcoin or an app like CryptoKitties—Solidity is going to be your go-to language.

Here's a quick look at some of the key features of Solidity:

  • Smart Contract Support: Solidity was specifically made for Ethereum, a platform built to support smart contracts. This means it's tailor-made for creating your very own smart contracts.
  • Ethereum Virtual Machine (EVM) Compatible: Solidity code runs on the EVM, which executes smart contract code on all nodes across the Ethereum network. This ensures the blockchain's decentralized nature.
  • Static Typing: Solidity is a statically typed language. This means you have to declare the type of each variable before you use it, making your code clearer and easier to understand.
  • Inheritance: Solidity supports inheritance in contracts. So, you can create a new contract that inherits properties from an existing contract—just like in object-oriented programming!

So, if you're pondering if you should start learning Solidity for blockchain development, knowing these features should give you a clear push in the 'yes' direction! Now, let's move on to why Solidity is used in blockchain development.

Why use Solidity in Blockchain development?

Now, you might ask, "Why should I start learning Solidity for blockchain development specifically? Aren't there other languages I could use?" While it's true that there are other languages out there, Solidity has some unique advantages that make it stand out. Let's discuss a few:

  • Designed for Blockchain: Solidity was crafted with blockchain in mind. The language is tailored to support the development of decentralized applications (dApps) and smart contracts, which are fundamental components of blockchain technology.
  • Highly Secure: Security is paramount in blockchain development. Solidity has features like static typing and contract-oriented programming that help you write safer, secure code.
  • Community Support: Solidity has a vibrant, active community of developers. This means you'll always have someone to turn to when you're stuck with a problem, and you'll never be short of resources to learn from.
  • Wide Adoption: Another reason you should start learning Solidity for blockchain development is its wide adoption. Many popular blockchain projects, including Ethereum itself, were built using Solidity. This means you'll find plenty of real-world examples and use-cases to learn from.

These advantages make Solidity a great choice for any aspiring blockchain developer. And don't worry if you're new to programming—Solidity is relatively easy to learn, especially if you're already familiar with JavaScript or Python. Now, let's move on and get a sense of what the basic syntax of Solidity looks like.

Basic syntax of Solidity

So, you've decided to start learning Solidity for blockchain development. Great choice! But where do you start? How about with the basics—the syntax. In this section, we'll go over some of the basic syntax you'll need to get started.

First things first, let's talk about comments. Like many programming languages, Solidity uses // for single line comments and /*...*/ for multiline comments. This is a good habit to get into; writing comments helps you and others understand what your code is doing.

Variables are a fundamental concept in any programming language, and Solidity is no exception. Solidity has two types of variables:

  1. State Variables: These are permanently stored in contract storage. They represent the "state" of a smart contract.
  2. Local Variables: These exist only inside function calls. Once the function has finished executing, these variables are erased.

Now, let's talk about data types. Solidity has various data types, including integers (uint for unsigned integers), boolean, address (for storing Ethereum addresses), and bytes (for binary data).

When you're writing a smart contract, you'll need to define it using the contract keyword. Each contract can contain declarations of State Variables, Functions, Function Modifiers, Events, Struct Types and Enum Types.

For example, a simple contract in Solidity might look like this:

contract SimpleContract {    // State variable    uint public count;        // Function    function incrementCount() public {        count += 1;    }}

This is a very basic overview, but don't worry—we'll dive into these concepts in more depth later on. The important thing here is to start getting comfortable with the look and feel of Solidity. As you begin to explore, you'll find that it's a powerful tool in your blockchain development toolbox.

How to set up Solidity environment

So, you're sold on the idea of learning Solidity for blockchain development. The next step? Setting up your Solidity environment. Don't worry! Even though it sounds intimidating, it's actually quite straightforward. Let's get you set up in no time.

First, you'll need an Integrated Development Environment (IDE). An IDE is a software application that provides comprehensive facilities to programmers for software development. For Solidity, the most popular IDE is Remix. It's a browser-based IDE, which means you can use it directly from your web browser without the need to install any additional software. Just type 'Remix Ethereum IDE' in your search bar, and you're good to go.

The next thing you'll need is a Solidity Compiler. As the name suggests, it's used to compile your Solidity code. The Remix IDE we just mentioned has a built-in Solidity Compiler. So, when you choose Remix, you're killing two birds with one stone!

You'll also need to install Node.js and NPM (Node Package Manager). You can download these from the official Node.js website. They'll provide the runtime environment needed to run your Solidity scripts.

Finally, you should install Truffle. Truffle is a development environment, testing framework, and asset pipeline for Ethereum. You can install Truffle using NPM with the command: npm install -g truffle.

And voila! You have your Solidity development environment set up. In the next sections, we'll delve into writing your first smart contract, understanding variables and data types, and more. So, stay tuned and get ready to dive deep into the world of Solidity!

Writing your first Smart Contract

Imagining writing your first smart contract might feel a bit like standing on the edge of a high dive platform for the first time. But don't worry, we're here to walk you through it step by step. Before you know it, you'll be taking the leap and coding your first smart contract in Solidity!

First off, let's get a simple definition out of the way. A smart contract is like a traditional contract, but it's executed automatically on the blockchain. It's a set of rules and conditions that are coded and carried out without the need for a third party.

Now, let's jump right in. Open up your Remix IDE and start a new file. Name it whatever you like, but make sure it has a .sol extension.

Your first line of code should define the version of Solidity you're using. This could look something like this:

pragma solidity ^0.8.4;

This line of code is crucial because it tells the compiler which version of Solidity to use. Now we're ready to start writing the contract.

contract MyFirstContract {}

That's it! You've just written your first smart contract. Of course, it doesn't do anything yet, but everyone has to start somewhere, right? In the following sections, we'll talk about variables, data types, and functions, so you can make your contract do all sorts of things. So, keep going, and remember: every expert was once a beginner too.

Variables and Data Types

Remember when you first started learning about variables in math class, and it felt like a whole new world was opening up? Well, get ready for that feeling again because understanding variables and data types is a fundamental step if you're considering whether or not you should start learning Solidity for blockchain development.

Here's a simple way to think about variables: they're like containers that hold information. In Solidity, you can have different types of containers (data types) for different types of information. Let's take a look at some of the most common ones:

  • bool: This is a basic data type that can hold one of two values: true or false.
  • uint: Short for 'unsigned integer', this data type can hold non-negative integers. 'Unsigned' means it can't be negative.
  • address: This data type stores an Ethereum address. It's a unique code that identifies a specific account on the Ethereum blockchain.
  • string: This is used to hold a sequence of characters, like a word or a sentence.

When you're declaring a variable, you need to specify its data type. For example:

bool isLearningSolidityFun = true;

This line of code declares a variable named 'isLearningSolidityFun' and assigns it the value 'true'. The variable is of the data type 'bool'.

The world of variables and data types in Solidity is deep and fascinating, and we've only just scratched the surface. But don't worry, with each line of code you write, you'll become more comfortable and confident. So, keep practicing, and remember, Rome wasn't built in a day!

Functions in Solidity

Picture this: you've just finished setting up a row of colorful dominos. With one small push, you can trigger a chain reaction, creating a mesmerizing display of falling dominos. Isn't that satisfying? This is somewhat how functions in Solidity work. You set them up with certain instructions and then call them into action.

Just like dominos, functions in Solidity are a sequence of actions that the computer performs one after another. They're like the building blocks of your smart contract. Functions help to simplify your code by breaking it down into smaller, more manageable sections. This makes your code easier to read, debug, and maintain.

So, how does a function look in Solidity? Let's take a look:

function greet() public pure returns (string memory) {    return "Hello, world!";}

This function, called 'greet', does not take any input parameters and returns a string "Hello, world!". It's a simple function, but it illustrates the basic structure of a function in Solidity.

The keyword 'function' starts the definition, followed by the name of the function. In this case, it's 'greet'. The parentheses '()' would hold any input parameters, but in this function, they're empty because 'greet' doesn't take any inputs. The 'public' keyword means that this function can be called from any other function in this contract or from other contracts. The 'pure' keyword indicates that this function does not alter the state of the contract. Finally, the 'returns' keyword is followed by the type of value the function returns.

Functions in Solidity are like the magic spells of blockchain development. By combining different functions in unique ways, you can create smart contracts that can do almost anything you can imagine. So, if you're still wondering "should I start learning Solidity for blockchain development?" — knowing that you can create such magic might help you decide.

Control Structures in Solidity

Imagine you're playing a game of chess. You're considering your next move. If you move your queen, you could checkmate your opponent, but if you don't, you could lose your rook. Just like in a chess game, control structures in Solidity help your program make decisions. They guide the flow of execution depending on certain conditions. In other words, they're the brain behind the operation.

There are several types of control structures in Solidity, but let's start with the most basic ones: 'if', 'else' and 'for'.

if (x > 10) {    // Execute some code} else {    // Execute some other code}

In this example, 'if' checks whether the variable 'x' is greater than 10. If it is, it executes the code within the first set of curly braces. If 'x' is not greater than 10, it executes the code in the 'else' section.

for (uint i=0; i<10; i++) {    // Execute some code}

The 'for' loop runs the code inside its curly braces a certain number of times. In this case, it starts by setting a variable 'i' to 0. Then it keeps running the code as long as 'i' is less than 10, and after each run, it increases 'i' by 1.

Control structures are what give your smart contract the ability to react and adapt to different situations. They're like the rule book that guides your contract's actions. So, if you're asking "should I start learning Solidity for blockchain development?" — consider this: learning Solidity gives you the power to create your own rule book for the blockchain world.

Error Handling in Solidity

Let's talk about error handling now. If you've ever tried to solve a Rubik's cube and ended up with an impossible configuration, you know how important it is to correct mistakes early. Similarly, in Solidity, error handling ensures that your smart contracts behave as expected, even when things go wrong.

In Solidity, we use two main mechanisms for error handling: 'require' and 'revert'.

require(someCondition, "Error message");

'require' checks if a certain condition is true. If it's not, it stops the execution and reverts all changes made in the current call. It can also provide a helpful error message to tell you what went wrong.

if (!someCondition) {    revert("Error message");}

'revert' is like the big red button you hit when things go south. It stops the execution and undoes all changes, just like 'require'. The difference is that you usually use 'revert' inside an 'if' statement when you need to check more complex conditions.

But why is error handling so important? In the world of blockchain, there's no 'undo' button. If your smart contract has a bug that leads to an incorrect transaction, it can't be reversed. That's why you need to catch and handle errors before they can do any harm. So, if you're thinking, "Should I start learning Solidity for blockchain development?", remember that Solidity gives you the tools to write secure and reliable code for the unforgiving blockchain environment.

Best Practices for Solidity Development

Just like tidying up your room makes it easier to find your favorite comic book, following best practices in Solidity makes your code easier to read, test, and maintain. So, whether you're just starting out or wondering, "should I start learning Solidity for blockchain development?", here are a few tips to keep in mind.

First off, always use the latest version of Solidity. It offers the best security, efficiency, and features. You wouldn't want to use your grandpa's old computer to play the latest video games, would you?

Next, be explicit about visibility. In Solidity, functions and state variables can be public, private, internal, or external. If you don't specify visibility, Solidity will choose for you. But it's like letting your little brother pick your clothes for school — you might not like the result!

Also, avoid loops when you can. Looping over large data structures can use up all the gas, stopping your smart contract in its tracks. It's like trying to run a marathon after eating a whole pizza — not a good idea!

Lastly, write tests for your code. Tests help you catch bugs before they become a problem. It's like checking your backpack before leaving for school — much better than realizing you forgot your math homework when you're already in class!

With these best practices in mind, you're well on your way to becoming a Solidity superstar!

If you're excited to dive deeper into the world of blockchain development after reading our beginner's guide to Solidity, check out the workshop 'Start Your web3 Journey' by Tom Glendinning. This workshop will provide you with the knowledge and resources you need to kickstart your journey into web3 and blockchain development.