สัญญา Solidity แรกของคุณ

Time to write your first smart contract! We'll build a simple Hello World in Solidity using the browser-based Remix IDE - no setup needed.

Remix IDE lets you write, compile, debug, and deploy Solidity contracts right in your browser. It's perfect for learning and quick prototyping.

Every Solidity file opens with a pragma that pins the compiler version. The code below means versions 0.8.0 up to (but not including) 0.9.0 are allowed.

Solidity code lives inside a contract, much like a class in OOP. You declare it with the contract keyword, a name, and curly braces, as shown.

A state variable is stored permanently on chain and defines your contract's state. Here we add a string called greeting; public makes it readable by anyone.

The constructor runs exactly once, at deployment, to initialize state. Here it sets greeting to "Hello CoddyKit!" the moment the contract goes live.

A view function reads contract state without changing it. This getGreeting is public and returns a string from memory, as shown below.

Here's the full Hello World contract. Paste it into Remix, compile, deploy to a test chain, then call getGreeting() to see it work.

Before deploying, a contract must be compiled - turning your Solidity into EVM bytecode. Remix has a built-in compiler with a handy Auto compile option.

Which part of a Solidity smart contract specifies the minimum compatible compiler version?

Recap: you built a Solidity contract with a pragma, a contract block, a state variable, a constructor, and a view function - all in Remix. Nice work!