What is Solidity?

IntermediateNov 23, 2023
Discover the essence of Solidity, Ethereum's smart contract language, and its impact on blockchain innovation.
What is Solidity?

Understanding one of the major programming languages that power the world of decentralized applications and smart contracts is a fundamental step for anyone venturing into the blockchain realm.

Solidity is not just another coding language; it is the driving force behind the creation of self-executing contracts and decentralized applications on the Ethereum blockchain and various other platforms. This article will delve into how Solidity works, exploring its significance, features, and real-world applications.

What is Solidity?

Solidity is a high-level object-oriented programming language for writing and running smart contracts on the blockchain. Best known for its connection to the home of DeFi, Ethereum, Solidity was created by Ethereum’s developers to create smart contracts that run with the Ethereum Virtual Machine on the network.

In the web3 developer space, Solidity is one of the most widely used programming languages, although it features elements from other popular languages like Javascript, C++, and Python. Solidity is a statistically typed language that supports inheritance, complex user-defined types, and libraries, elements essential for smart contract functionality. Solidity is a popular choice among smart contract developers because it is easy to use. The nature of the programming language (high-level) replaces typing in bitcode (ones and zeros) with a combination of letters and numbers.

Background of Solidity Programming Language

Despite its current reputation as one of the most widely used programming languages, Solidity has humble beginnings that go as far back as 2014. In 2014, Gavin Woods, Christian Reitwissner, and other developers of the Ethereum Foundation created Solidity to support the development of the upcoming Ethereum network. The developers created Solidity as a language that developers found easy to use, expressive, and compatible with the Ethereum Virtual Machine, a runtime environment central to running smart contracts.

Solidity is inspired by existing languages like Python, C++, and JavaScript. Still, its originality comes from unique concepts and syntax embedded specifically to deal with smart contracts, state variables, modifiers, and events.

How Does It Work?

Solidity is primarily used to write smart contracts. Smart contracts are the backbone of the Ethereum network, and they refer to programs that run on the Ethereum Virtual Machine (EVM) and serve multiple functions, mostly involving the automation of transactions on the network. The EVM works as the record keeper for Ethereum’s “global computer,” meaning that the EVM maintains the global state of the network, including addresses, account balances, and token holdings.

Solidity contracts are compiled into bytecode and read by the EVM, which means that, theoretically, developers can write Ethereum smart contracts directly with bytecode. However, writing directly with bytecode is hardly used because it is more technical and error-prone. As such, using high-level languages like Solidity allows developers to focus on the logic and functionality of the code instead of dealing with the complexities of writing in bytecode. As a result, developers can code more efficiently and focus more on creating smart contracts that are easier to read, write, and maintain.

Solidity is subject to periodic version updates, which are released on Github. Smart contracts are immutable, meaning that once they are deployed on-chain, they cannot be reversed. Because Solidity itself is constantly evolving, the immutability of smart contracts affects it because any errors or shortcomings in a contract’s code cannot be easily fixed once it’s live. The reason is that each version has distinct behaviors and features, which could influence the contract’s functionality and how it interacts with other elements within the Ethereum ecosystem.

In recent times, developers have preferred to use proxy contracts and upgradeable contracts. Proxy contracts enable the execution of another contract’s code. Proxies act as intermediaries, forwarding calls and transactions to the intended contract while allowing for additional functionality, such as access control or logging. Upgradeable contracts essentially involve smart contracts that can be upgraded without losing their original state.

It must be noted that the version of Solidity used at the time of the smart contract’s creation is essential, too, because that will determine the smart contract’s behaviour and features. Each line of source code on every Solidity smart contract, however simple, must begin with a declaration of which version of the Solidity compiler should be used for that particular piece of code. This declaration is what is known as the “version pragma.”

Main Features of Solidity Language

Solidity is regarded as the gateway to the world of decentralized applications and blockchain-based smart contracts. Some key features that make Solidity such a productive programming language include the following.

Built-in Functions and Data Types

Developers don’t need to write conditional statements or loops to perform actions dependent on certain conditions. Instead, they can specify the conditions directly in their source code, and the smart contract will execute the specific action only when those conditions are met. This makes the coding process much more manageable.

Solidity also supports the most common data types like integers, floating point numbers, strings, arrays, and maps. Developers can also define their own data types and use them in their smart contracts.

Coding Environment

Solidity’s compiler consistently checks the code for errors as you write it and alerts you about any potential problems. This is especially helpful when developing large and complex dApps and smart contracts.

Use Cases of Solidity Programming Language

Solidity can be typically used to create smart contracts that enhance transparency and traceability in supply chain management. Solidity-powered smart contracts can also help prevent counterfeiting and improve trust in the supply chain process by recording transactions and verifying the authenticity of products.

Solidity is frequently used to develop blockchain-based games and virtual worlds featuring asset ownership, in-game economies, and provable scarcity. Solidity opens up new possibilities for unique digital assets and player interactions. Developers have also used Solidity to create decentralized exchange logic, auction mechanisms, lending protocols, conditional payments, etc.

Moreover, Solidity is used to implement NFTs. It has also enabled the creation of DAOs, which are self-governing organizations that operate on smart contracts, in turn allowing for transparent decision-making and governance.

Projects Supporting Solidity

Avalanche

Avalanche is a cutting-edge blockchain platform that has gained some prominence in the world of DeFi and smart contracts. On Avalanche, transactions are processed in seconds, making it an efficient platform for DeFi applications and token swaps. Its EVM compatibility allows it to work seamlessly with Solidity-written smart contracts, also contributing to Avalanche’s adoption by developers.

Monax

Monax is a leading blockchain project designed to revolutionize, simplify and optimize how businesses handle legal agreements.The platform enables the creation of legally binding agreements and automates various aspects of contract execution and management. It is particularly beneficial for enterprises, as Monax offers them a safe and efficient way to manage the entire contract lifecycle.

Solidity helps by assisting the creation of self-executing smart contracts, while Monax extends this technology to legal agreements, allowing businesses to define their contractual rules in a programmable and self-executing format.

Solidity vs. Rust

Solidity and Rust share some basic similarities. For one, both programming languages offer multichain compatibility. While Solidity was designed primarily for Ethereum, it supports layer 2 blockchains, sidechains, and, of course, EVM-compatible layer 1 blockchains like Moonbeam and Avalanche-C chain. Rust also supports a glossary of blockchains such as Near and Solana while still being the programming language that inspired the Move and Sui languages.

Additionally, both languages are Turing complete languages. This means that both languages can solve any computational problem regardless of complexity. Programming languages inherited this feature from the Turing machine, developed by Alan Turing.

Conversely, Solidity and Rust possess stark differences. For instance, Solidity is a high-level language offering a high level of abstraction from the computer system architecture. As a result, Solidity is easier to learn and use, making it a more user-oriented language. On the other hand, Rust is a low-level language closer to the computer’s hardware and provides good memory efficiency and speed, making it a more machine-oriented language.

Furthermore, both programming languages use differing programming paradigms. A programming paradigm is the approach used when solving a problem. Solidity, on the one hand, is an object-oriented language since it uses the object-oriented paradigm to solve problems. On the other hand, Rust is a multiparadigm language, meaning it permits using different paradigms or approaches to solve problems. Some of the paradigms Rust supports are object-oriented, functional, and imperative, amongst several others.

Solidity vs. JavaScript

Solidity and Javascript are two of the most common programming languages but share very few similarities. Javascript was one of the biggest inspirations for Solidity, but now the only significant similarity is that Solidity uses the ‘function’ keyword for defining functions. Solidity’s syntax also has a JavaScript-like appearance, but this is a little deceptive because Solidity and JavaScript operate quite differently.

Conversely, both languages differ greatly. JavaScript can be run directly, while Solidity requires compilation because JavaScript is an interpreted language, not a compiled language like Solidity. Additionally, Solidity has the capability to transfer money. However, this is not a built-in capacity, so developers must utilize an external application programming interface (API).

Another difference between both languages is that with Solidity, once a smart contract is deployed on Ethereum, it is immutable, and the code can no longer be edited. JavaScript also does not allow direct interaction with code running on other servers, but if the server offers an API that permits access, then the developer can edit the code.

Best Resources to Learn Solidity

Learning Solidity is one of the first steps to take when becoming a web3 developer, as it is the fundamental programming language for developers who wish to create and deploy smart contracts on the Ethereum network. When choosing a course to learn about Solidity, it is crucial to evaluate the topics, format, and other supplemental resources provided. To attain the best knowledge about Solidity, you could consider a few resources to use, including the following.

Gate Learn

Gate Learn offers a course titled “Blockchain Development Platforms and Smart Contracts” where they provide an overview of popular blockchain development platforms, as well as their key features. While it is a comprehensive course, it offers key insight into the process of developing a basic blockchain application using Solidity.

With this course, you will learn how to set up the development environment, write the smart contract, define the contract’s state variables, create functions to interact with the contract, compile, and deploy the contract.

Gate Learn also provides a course titled “Smart Contracts 101: A Basic Introduction” where you can learn about the fundamentals of smart contracts and their use cases across industries and also interact with external contracts and deploy your own smart contracts using MetaMask

WTF Academy

WTF Academy is an open source, community-driven blockchain learning platform offering full courses on web and blockchain development such as JavaScript, On-chain analysis, EVM Opcodes, and Solidity. It is sponsored by the Ethereum Foundation, StarkWare, and Optimism. It has also received donations from Gitcoin and Mirror.

WTF Academy offers five Solidity courses for novices (Solidity 101, 102, 103, Solidity 104 Security, and Solidity 104 Tx Analysis). These courses are free and provide certificates upon completion.

The Complete Solidity Course – Blockchain – Zero to Expert [Udemy]

This is a paid Udemy course serving as a one-stop solution for learning Solidity. The course will help you start from scratch with the most fundamental topics and will take you to an advanced level, where you can build complex smart contracts and dApps. It is a complete course, so you will not need any supplementary resources to get all the necessary information.

In this course, you’ll learn about the Solidity programming language, how to write smart contracts, and also understand EVM, the Ethereum blockchain, and how other blockchain platforms work. You can also apply your knowledge with over 30 assignments and challenges.

Learn Solidity: Programming Language for Ethereum Smart Contracts [Blockchain Council]

Blockchain Council recently developed the Learn Solidity Program to help developers understand the basics within a few hours. With this free course, you should have a clear idea about the development of dApps on the Ethereum blockchain.

The course will teach you the basics of Ethereum, smart contracts, and other blockchain platforms. You will also learn how to install and set up the Solidity Development Environment, build live applications, and deploy smart contracts in Solidity.

Ethereum Blockchain Developer Bootcamp With Solidity [Udemy]

This course requires no prior knowledge to complete. The course will give you a theoretical and practical understanding of smart contracts, and you will learn how to use Ethereum’s major core development tools. It also features step-by-step video tutorials to facilitate better understanding.

This course is a paid course, and it is recommended for those aiming to be Ethereum developers. Completing this course will make you proficient in Solidity, Web3, Remix, Metamask, Truffle, and other blockchain concepts.

Author: Tamilore
Translator: Cedar
Reviewer(s): Matheus、KOWEI、Ashley He
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