Now I know we've gone over a lot of advanced Solidity here, so let's do a quick refresher of what we've learned so far. Whenever we interact with a contract, we always need the address and the API. Compiling an interface allows us to get

that ABI very easily for us to interact with another contract. When we combine the contract address with the interface, we can easily call the functions on that contract. Chainlink price feeds are an easy way to get data, especially pricing data from the real world, into our smart

contracts. When working with math in Solidity and the EVM in general, decimals don't work, so we need to always make sure we're using the correct number of units whenever we interact with our contracts. `message.value` and `message.sender` are known as globally available units in Solidity and they

refer to the sender of a message of the current call or the number of wei sent with a message or transaction. There's a whole bunch of these and you can view them all in the Solidity documentation.

Lesson 4 Part 13 | Recap II - Solidity & Foundry Full Course

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Solidity refresher: Contract interaction and ABIs

Contract interaction requires address and API (ABI).

Compiling an interface simplifies ABI retrieval for contract interaction.

Combining contract address and interface enables function calls.

Chainlink price feeds facilitate real-world data integration into smart contracts.

Solidity and Chainlink: Data integration and mathematical considerations

Solidity and EVM handle units, not decimals, requiring careful unit management.

`message.value` represents wei sent in a transaction.

`message.sender` identifies the transaction sender.

Additional globally available units are documented in Solidity documentation.

Lesson 4 Part 13 | Recap II - Solidity & Foundry Full Course

Lesson 4 Part 13 | Recap II - Solidity & Foundry Full Course

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