Functions serve as the building blocks of smart contracts. Functions can be either public, ie they are publicly available for anyone to see and can directly interact with public state, or private, meaning they are executed completely client-side in the PXE. Read more about how private functions work here.
For a more practical guide of using multiple types of functions, follow the token tutorial.
Currently, any function is "mutable" in the sense that it might alter state. In the future, we will support static calls, similarly to EVM. A static call is essentially a call that does not alter state (it keeps state static).
Every smart contract has a private
constructor function which is called when the contract is deployed.
A special constructor function must be declared within a contract's scope.
A constructor doesn't have a name, because its purpose is clear: to initialize contract state. In Aztec terminology, a constructor is always a 'private function' (i.e. it cannot be a public function). A constructor behaves almost identically to any other function. It is just important for Aztec to be able to identify this function as special: it may only be called once, and will not be deployed as part of the contract.
There are also special oracle functions, which can get data from outside of the smart contract. In the context of Aztec, oracles are often used to get user-provided inputs.
Explore this section to learn:
- How function visibility works in Aztec
- Public, private, and unconstrained functions, and how to write them
- How to write a constructor
- Calling functions from within the same smart contract and from different contracts, including calling private functions from private functions, public from public, and even private from public
- Oracles and how Aztec smart contracts might use them
- How functions work under the hood