Chapter 4

Solidity Basics

Solidity is the language most beginners use to write Ethereum contracts. Its syntax feels familiar to JavaScript developers, but its purpose is different: define state, expose functions, and describe what should be logged on chain.

Most beginner contracts can be understood by separating what they store, what they do, and what they announce.

Core contract parts

Part	Role	Example
State	Persistent variables the contract remembers	owner, balances, totalSupply
Functions	Callable logic that reads or changes state	mint(), transfer(), vote()
Events	Logs for off-chain apps and explorers	Transfer, Approval, Deposited

Once those three pieces click, reading simple Solidity files becomes much less intimidating.

State variables live in storage, which means they survive after a transaction ends. Functions define behavior, from simple reads to complex token swaps or voting flows. Events do not change state, but they help wallets and dashboards understand what happened.

Solidity also includes types, control flow, and error handling, but these three contract parts are the best mental anchor for new readers. They tell you what the contract knows, what actions it permits, and what signals it emits.