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Defining Functions

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. However, we also support support static calls, similarly to EVM. A static call is essentially a call that does not alter state (it keeps state static).

Initializer functions

Smart contracts may have one, or many, initializer functions which are called when the contract is deployed.

Initializers are regular functions that set an "initialized" flag (a nullifier) for the contract. A contract can only be initialized once, and contract functions can only be called after the contract has been initialized, much like a constructor. However, if a contract defines no initializers, it can be called at any time. Additionally, you can define as many initializer functions in a contract as you want, both private and public.

Oracles

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: