A smart contract is a self-executing program in which the agreement and terms of service between buyers and sellers are encrypted directly into lines of code. Smart contracts allow trusted agreements and transactions to be initiated between anonymous parties without the need for a central authority or enforcement mechanism. Nft Development Smart contract services in the crypto space have evolved the capabilities of blockchain-based systems
Smart contracts in the blockchain field have the following characteristics: the rules are open and transparent, and the rules and data in the contract are visible to the outside world; all transactions are public, and there will be no false or hidden transactions. Therefore, the blockchain technology we often say has the characteristics of “openness and transparency” and “immutability”, but it is actually given to the blockchain by smart contracts.
In traditional contractual behavior, people make rules and enforce them. Of course, it is also up to people to define when boundary issues or exceptions are encountered. But with smart contracts, these are different. Developers formulate a set of rules through smart contracts, which are then published online. Humans interact with smart contracts, and machines complete the business part, thus avoiding possible cheating when humans execute them.
Advantages of blockchain-based smart contracts
- Contracts are written into the blockchain in digital form. Due to the uniqueness of the blockchain, data cannot be deleted or modified, only added. The whole process is transparent and traceable, ensuring the traceability of history;
2. Since the behavior will be permanently recorded, the interference of malicious behavior on the normal execution of the contract can be avoided to a large extent;
3. Decentralization, avoiding the influence of centralized factors, and improving the cost efficiency of smart contracts;
4. When the contract content When satisfied, the code of the smart contract will be automatically activated, which not only avoids the manual process, but also ensures that the issuer cannot default;
5. The state machine system is constructed through the consensus algorithm that comes with the blockchain, so that the smart contract can run efficiently.
The Web3 community is full of expectations for the non-fungible band currency (NFT). While no killer app has yet emerged, the technology has reshaped digital asset ownership, identity systems, innovation paradigms, and how communities operate.
Because NFTs are digital assets that can be bought and sold, and NFT exchanges collect NFT information and match buyers and sellers, NFT exchanges are an essential part of the ecosystem.
This tutorial explains how to use Solidity to build the “backend” of an NFT exchange, and how to develop smart contracts that carry the business logic of the exchange. In the code, we will create a NftMarketplace.solsmart contract and a token contract compatible with the ERC-721 (NFT) standard, and then display this NFT on our exchange.
You need to have some programming experience, if you know some basic Javascript, you can complete the whole project development. Of course, it would be better if you can be familiar with the terminology of Ethereum. The relevant knowledge of Ethereum can be learned by browsing the official website of Ethereum.
Project environment construction
In this project, we will use yarn, run npm install -g yarnto install it globally. Also, you need to make sure you have Node.js on your machine, run node –versionto check if it is installed.
In addition, Hardhat will be used to compile, deploy, test and interact with our smart contracts. Hardhat is an Ethereum development environment. For related knowledge, please browse the novice tutorial on Hardhat’s official website.
I’ll use <<root>> to refer to the project directory, open the command line, go to the project directory, open the IDE (you can use any IDE that supports javascript, like VSCode).
In the project directory, create a package.jsonfile and copy the contents of this file . This file will contain NPM dependencies, many of which are required by Hardhat. Then run yarn installto install all dependencies. When the installation is complete, look at the node_modulesfolder , this folder will contain all downloaded dependencies.
This tutorial will use Hardhat’s native blockchain network, which means we’re not actually touching Ethereum’s mainnet and testnets. If you want to test on an Ethereum testnet such as Rinkeby, please refer to the README of the Repo.