The ERC-721 standard helps make buying and selling unique digital items (NFTs) safe and reliable. It is crucial to secure transactions between two parties. That is where escrow services come in. They act like a safety net, holding an NFT until everyone agrees and all rules have been met. Let's explore how we can develop an escrow using the ERC-721 standard using OpenZeppelin implementation.
A Set structure, as used in many programming languages, is a collection of distinct elements where each item is unique, and no duplicates are allowed. This data structure is especially valuable when you need to efficiently check the existence of an item, maintain an organized collection of items without repetition, or quickly retrieve unique elements. Solidity programming language for Ethereum smart contract development does not natively support the Set data structure. Developers need to create their own structures or utilize external libraries to replicate Set functionalities, such as ensuring the uniqueness of elements within a collection.
NFT minting on Ethereum can be expensive due to the high gas fees associated with executing intelligent contract transactions on the blockchain. Previously we learned how to use the ERC-721 standard, but there is an improved standard, ERC-721A, by Azuki. It gives enormous gas savings when minting multiple NFTs in one transaction. Minting five NFTs can save 7.2 times gas compared to the original ERC-721 standard. Let's check it out in this article.