Ethereum Blockchain Development with Solidity and Next.js/

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Source File Layout

Source File Layout

Learn the sections and features of a regular Solidity smart contract source file.

We'll cover the following...

Coding components

We learned about Remix and its basic features by writing a simple test contract. In this lesson, we’ll go through the different sections of the code to understand the components of a Solidity file and what each one does. Let’s begin with the file below:

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// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;
import "hardhat/console.sol";
/**
 * @title Contact
 * @dev Store & retrieve contacts of friends and family
 */
contract Contact {
    // contract code goes here.
}

  • Line 1: We define the SPDX identifier.

  • Lines 3–5: We set the Solidity version and import Hardhat’s console.sol library to log information and errors.

  • Lines 11–13: We define our smart contract.

SPDX license identifier

This component should be the first thing in our smart contract code file, written in the form of a comment.

Note: The SPDX License List contains commonly found licenses and exceptions used in ...