Mastering Blockchain Programming with Solidity

Structure of a contract

Just like in an object-oriented language such as Java, where we have classes, similarly we have contracts in Solidity languages. Each Solidity contract can contain declarations of one or many state variables, constants, a constructor function, enumerations types, function modifiers, events, functions, and struct types. Furthermore, a contract can inherit from other contracts as well.

You can also define special kinds of contracts called libraries and interfaces. Libraries are deployed only once along with your contract deployment. Interfaces cannot have function definitions, variables, struct types, or enums. We have a separate chapter where we will talk about libraries and interfaces in detail.

Normally, the structure ...