Article

Solidity & Smart Contracts: A quick introduction

October 19, 2022

There are now two new terms sweeping the world of blockchain development: Solidity and smart contracts. In this article, we explain what these are, and why people are interested in them.

What Are Smart Contracts?

Smart contracts, also known as crypto-contracts, are digital, self-executing contracts that help verify a transaction’s credibility without the involvement of third parties. They are typically used to automatically execute the terms of an agreement so that all participants can be immediately sure of the outcome. In this sense, they specify the rules and behavior for transferring digital assets. 

What Are The Advantages of Smart Contracts?

Smart contracts programs are stored in a blockchain that runs when predetermined conditions are met and verified. Agreement terms between buyer and seller are written into lines of code that exist across a distributed decentralized blockchain network, making them traceable, transparent, and irreversible.

Only parties who have been granted permission can see the results. The blockchain is updated when the transaction is complete. If either party fails to uphold their end of the bargain, the money is sent back immediately.

Smart contracts offer the following benefits:

  • They’re fast, accurate, and efficient: Contracts are immediately executed once conditions are met. Since they are digital and automated, there’s no paperwork to process and no time spent fixing mistakes that can occur when manually filling in documents.

  • They instill trust and transparency: Since third parties are not involved and participants share encrypted transactions, participants don’t have to worry if information has been altered for personal benefit.

  • They’re secure: Blockchain transaction records are encrypted, so they are difficult to hack and cannot be changed or altered in any way. Because each record connects to previous and ensuing records on a distributed ledger, hackers would have to alter the entire chain to change a single record.

  • They're cost-effective: By eliminating third parties, companies lower transaction costs. In industries like real estate and lending, cutting out pricey third-party fees can lower costs significantly.

Smart contracts are becoming increasingly attractive to businesses looking to enhance transaction security. Smart contracts can automate many processes, which saves time and money. In addition, smart contracts are based on secure and tamper-proof blockchain technology, making them ideal for businesses that need to store and manage sensitive data. 

What Is Solidity?

Solidity is an object-oriented, high-level programming language developed specifically for creating and implementing smart contracts on various blockchain development platforms, particularly Ethereum. Initially developed in 2014, Solidity has attracted the attention of businesses who want to switch from traditional to “smart” contracts. 

At their most basic, Solidity smart contracts enable highly secure digital transactions that don’t involve third parties. Smart contracts are baked into blockchain technology, making them traceable, transparent, irreversible, and immediate. An estimated 90% of the world’s smart contract development is done with Solidity.

Solidity is the primary programming language for developing smart contracts on the Ethereum blockchain, the second-most popular blockchain.  Since it’s open source, anyone can use Ethereum, making it the platform of choice for creating and implementing smart contracts. 

How does Solidity compare to other programming languages?

Solidity uses ECMAScript-like syntax, similar to Javascript. However, it is a compiled language that is executed on the Ethereum Virtual Machine (EVM), not an interpreted language. It is also influenced by C++ and Python, so if you have a background in these, you’ll be off to a good start. The language is statically typed, supports inheritance, liberties, and complex-user-defined types. 

Solidity smart contracts are built on a blockchain, so they cannot be altered or deleted, making them a very secure way to transfer anything of value. However, this can also work as a disadvantage. The code behind Solidity smart contracts must be impeccable and error-free. You cannot correct mistakes or reverse transactions, and updating the Ethereum code is the only way to fix exploits, which isn’t an easy task.

Here is an example of some Solidity code with simple set and get accessors.

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.4.16 <0.9.0;

contract SimpleStorage {
    uint storedData;

    function set(uint x) public {
        storedData = x;
    }

    function get() public view returns (uint) {
        return storedData;
    }
}

Some Other Solidity Use Cases

With Solidity, you can create smart contracts for use cases such as crowdfunding, blind auctions, and multi-signature wallets. Let’s take a look at each of these examples.

Crowdfunding: Smart contracts for crowdfunding can solve various problems concerning commissions for third parties, data management issues, task posting and receiving, reward assignments, and more. Solidity smart contracts can work better and more efficiently for crowdfunding than non-trusted federal systems.

Blind auctions: Implementation of blind auctions using Solidity is quite simple on Ethereum. An open sale can be created where every person is aware of each other’s bid. Then, a blind auction can be designed that makes it impossible for anyone to see other bids until the bidding process ends.

Multi-signature wallets: Most cryptocurrency wallets need one signature or private key to sign and process a transaction. A multi-signature wallet requires one or more signatures to sign a transaction for processing. Developing multi-signature wallets through Solidity can mitigate the risk of losing your private key or accidentally sending a transaction.

How do I learn more about Solidity?

If you’re interested in developing applications using Solidity, we recommend the Pluralsight course “Developing Applications on Ethereum Blockchain.” In it, you’ll learn the basics of blockchain and Ethereum, as well as the core skills for writing smart contracts using the Solidity programming language.

You can also visit the official Solidity language website to read the official documentation, including any breaking changes in the latest version.