Solidity is the programming language for writing Smart Contracts. It is compiled to bytecode executable on the Ethereum Virtual Machine (EVM). Solidity supports inheritance, libraries and complex user-defined types, among other features that make it a good choice for developing smart contract applications.
In this tutorial, we will create a sample smart contract and deploy it to the Ethereum blockchain using Remix. The remix is an online compiler, IDE and debugger for Solidity, which is a JavaScript-like language for writing Ethereum smart contracts.
What exactly is Ethereum?
Let’s start with an overview of Ethereum before moving on to smart contracts and Solidity. Ethereum is a blockchain-based, open-source, public, distributed computing platform featuring smart contract functionality.
It has its cryptocurrency called Ether which is used for paying transaction fees and other services on the network.
It provides a decentralized virtual machine that can execute scripts using an international network of public nodes.
The Ethereum Virtual Machine (EVM) executes scripts using an international network of public nodes to store and run smart contracts programs.
What are Smart Contracts?
Let’s jump into the depth of smart contracts and try to understand the deep concepts of smart contracts.
Smart contracts are the new way to trade on the internet. They are like traditional contracts, but they are executed automatically by a computer without human intervention. Moreover, It’s an independent Solidity script compiled into JSON and uploaded to a specific blockchain address.
We can execute implemented smart contracts accordingly to a particular address by inputting accurate data together with Ethereum to call the compiled and deployed Solidity function, just like we can contact a URL endpoint of a RESTful API to run some functionality through an HttpRequest.
Smart contracts are distributed to the decentralized database for a price proportional to the storage size of the enclosing code. It can alternatively be characterized as a set of code stored in the blockchain network that defines requirements that all contract participants must agree to.
Nick Szabo first introduced the idea behind smart contracts in 1994, and they have been widely used since then. They are usually programmed in Solidity, a high-level programming language designed to develop smart contracts and decentralized applications on the Ethereum platform.
Prerequisites to Create Smart Contract using Solidity
The first step is to install the Solidity compiler and IDE. The IDE is not strictly necessary, but it does writing and debugging smart contracts easier.
The second step is to create a library for your contract code. This library should contain all of the contract code you want to share between contracts or across projects. This allows us to avoid repeating ourselves and also helps us keep track of what we have written before.
The third step is to install and set up a metamask. MetaMask is a wallet and an Ethereum browser in one. It lets you communicate with smart contracts and decentralized applications (dApps) via the web without downloading any application. All you have to do is install MetaMask as a Chrome extension, set up a wallet, and send Ether.
Although MetaMask is now only accessible for the Google Chrome browser, it is likely to be made available for Firefox in the future.
You may either import an existing wallet or create a new wallet after downloading and installing it as a Chrome extension. To deploy Ethereum smart contracts on the network, you’ll need some ethers in your Ethereum wallet.
read also: How to Become a Solidity Developer
Steps to Create Ethereum Smart Contract using Solidity
This is a guide on how to write an Ethereum Smart contract using Solidity.
Step 1: Use Remix Editor
The remix is a browser-based IDE that enables you to create Ethereum smart contracts using Solidity. It also provides a browser-based Remix IDE and Solidity compiler, which can compile and deploy your contract.
The remix IDE has a user-friendly interface that enables developers to create, debug, deploy and interact with smart contracts. It provides a complete set of tools and libraries that allow developers to write and compile their code while remaining in one place.
Moreover, Remix has some great features like autocomplete, Highlighting syntax and errors, Web3 objects are injected into functions, Analysis of static data, Debugger built-in, Environment for testing and deployment, which makes it easy for developers.
The first step is the Remix IDE on your browser by following this link: https://remix.ethereum.org/.
You can now start writing your smart contract by clicking “Create New File” in the top left corner of Remix’s window and selecting.
Step 2: Create a file called “MyContract.sol” in the contracts directory.
.sol is the file extension for smart solidity contracts. MyContract.sol is the file’s name where this contract will be saved.
Step 3: Write the following code in the MyContract.sol file:
// SPDX-License-Identifier: MIT
pragma solidity >=0.4.0 <0.7.0;
contract MyContract {
string storedData;
function set(string memory x) public {
storedData = x;
}
function get() public view returns (string memory) {
return storedData;
}
}
The Software Package Data Exchange® (SPDX®) identifier is used to designate the licence under which the Solidity file will be shared ‘/ SPDX-License-Identifier. It is strongly suggested that you incorporate it in your code, and if you don’t, the compiler will give an error.
Secondly, we used the pragma line. The “pragma” line at the top of the Solidity source file is used to set the compiler edition. The purpose of the Pragma line is to inform the compiler about the version you’re dealing with.
So, that’s how you write an Ethereum smart contract. Although this is a basic one, it is enough to give you an idea of creating a smart contract.
Step 4: Compile the smart contract
Let’s compile our code as mentioned above by clicking “Compile” on the right side of the screen, which will produce a new hexadecimal string in the “Output” tab.
Step 5: Deploy the Ethereum Smart Contracts
Let’s discuss how to deploy smart contracts.
- Switch to the main Ethereum network at metamask to activate your smart contract.
- Add some actual ethers.
- Now, use Remix to deploy your smart contract.
- After a smart contract has been successfully deployed, choose a smart contract for verifying.
- Now you must verify your smart contract by clicking “verify the contract” on this page.
- Copy and paste your intelligent contract code into Etherscan. Use the same compiler version you used for Remix to compile your code.
- Select “optimization” from the drop-down menu. If you selected optimization during Remix, click Yes; otherwise, select No.
- Verify by clicking the button.
- If there are no issues, it will just take a few minutes for your smart contract to go live.
So we have learnt how to write a simple Ethereum smart contract using solidity and remix editor. Now, to better understand Ethereum smart contracts, let’s discuss their benefits in detail.
Benefits of Smart Contracts:
Smart Contracts are self-executing contracts with the terms of the agreement between buyer and seller being directly written into lines of code.
Every time a transaction is made, its details are recorded as a “block” on a “public ledger” called the “Blockchain”. The Blockchain is continuously growing and is shared with every computer with a Bitcoin wallet, which anyone can download for free.
Smart Contracts provide advantages in many different areas:
- Speed: Smart contracts execute transactions automatically and securely without any third party interference.
- Cost: Smart contracts reduce or eliminate third party costs by providing users with an automated way to trade assets or share information.
- Transparency: All information about transactions are stored publicly on the Blockchain, eliminating fraud and making it challenging to alter the record
- Security: Ethereum uses cryptography to store data securely, making it difficult for anyone to tamper.
Conclusion
In this article, we explored the essential features of a Solidity contract and how to use the Remix IDE to develop, compile, and deploy a simple Smart Contract.