Struggling with ERC-20 & ERC-721 in Interviews—Need Advice!

ERC-20 and ERC-721 standards are super important for smart contract development on Ethereum. To put it simply, ERC-20 is all about fungible tokens, which means they’re interchangeable and have the same value—think of them as cryptocurrencies or in-game currencies.

On the flip side, ERC-721 is for non-fungible tokens (NFTs), which are unique and can’t be swapped on a one-to-one basis—perfect for digital art or collectibles.

If you’re building a decentralized application (dApp) that includes both types of tokens, you’ll need to work with these standards in your smart contracts. For fungible tokens, using ERC-20 will make sure your tokens are compatible with wallets and exchanges, so users can easily transfer and trade them. You’ll want to implement basic functions like transfer, approve, and transfer for smooth interactions.

When it comes to NFTs, ERC-721 lets you create one-of-a-kind digital assets. You’ll be implementing functions like mint, transferFrom, and ownerOf to manage these unique items. By sticking to these standards, you’ll ensure your dApp is user-friendly and fits well into the wider Ethereum ecosystem, setting you up for success!

How can implementing ERC-721 extensions like Metadata and Enumerable hinder interoperability with marketplaces and dApps relying on these features?
How does skipping the ERC-721 Metadata and Enumerable extensions impact the compatibility of ERC-721 tokens with NFT marketplaces and dApps? For example, without ERC-721 Metadata, marketplaces may not pull in token details like images, names, or descriptions from the contract.

Additionally, without ERC-721 Enumerable, marketplaces may have trouble showing all tokens in a collection or displaying all tokens a specific user owns. How essential are these extensions for reliable display and trading across platforms? Seeking insights on real issues or limitations encountered by omitting these standards.

Skipping the ERC-721 Metadata and Enumerable extensions can cause significant issues for NFT compatibility with marketplaces and dApps.

ERC-721 Metadata provides essential details about each token, such as name, symbol, and tokenURI. The tokenURI often links to JSON files that hold the image, description, and other properties for the token. Without Metadata, marketplaces cannot retrieve this information directly from the contract, leading to blank or incomplete displays. If Metadata is missing, custom workarounds are needed, but they lack consistency and prevent smooth interaction with platforms expecting standard formats.

ERC-721 Enumerable enables the contract to list tokens and manage collections efficiently. This extension allows platforms to see all tokens held by an address or view every token within a project. Without it, marketplaces cannot easily fetch lists or display full collections, affecting features like pagination and filtering. This makes it hard to show users all tokens they own or to showcase the entire collection of tokens, especially on larger marketplaces.

In summary, omitting Metadata and Enumerable limits usability and visibility. If reaching a wide audience and ensuring seamless platform integration are priorities, including both extensions is essential for an optimized and accessible NFT experience.