Hardhat is primarily designed for Ethereum development and supports several programming languages that are essential for building decentralized applications (dApps) and smart contracts. Below are the main languages supported by Hardhat:

1. Solidity

Solidity is the primary programming language for writing smart contracts on the Ethereum blockchain. Hardhat has built-in support for Solidity, allowing developers to compile, deploy, and test their contracts easily.

Here is a simple example of a Solidity contract:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract SimpleStorage {
    uint256 private storedData;

    function set(uint256 x) public {
        storedData = x;
    }

    function get() public view returns (uint256) {
        return storedData;
    }
}

This contract allows you to set and get a value, demonstrating the basic structure and syntax of Solidity.

2. JavaScript

JavaScript is extensively used in Hardhat for scripting, testing, and deploying smart contracts. Developers can write deployment scripts, test cases, and interact with their contracts using JavaScript.

Here is an example of a deployment script written in JavaScript:

async function main() {
    const SimpleStorage = await ethers.getContractFactory("SimpleStorage");
    const simpleStorage = await SimpleStorage.deploy();
    await simpleStorage.deployed();
    console.log("SimpleStorage deployed to:", simpleStorage.address);
}

main()
    .then(() => process.exit(0))
    .catch((error) => {
        console.error(error);
        process.exit(1);
    });

This script deploys the SimpleStorage contract and logs its address to the console.

3. TypeScript

Hardhat also supports TypeScript, a typed superset of JavaScript that adds static types. This makes it easier to catch errors during development and enhances code readability.

To use TypeScript in Hardhat, you need to install the necessary packages:

npm install --save-dev typescript ts-node @types/node

Here is an example of a TypeScript deployment script:

import { ethers } from "hardhat";

async function main() {
    const SimpleStorage = await ethers.getContractFactory("SimpleStorage");
    const simpleStorage = await SimpleStorage.deploy();
    await simpleStorage.deployed();
    console.log("SimpleStorage deployed to:", simpleStorage.address);
}

main()
    .then(() => process.exit(0))
    .catch((error) => {
        console.error(error);
        process.exit(1);
    });

This TypeScript script performs the same function as the JavaScript script but benefits from type checking.

4. JSON

While not a programming language in the traditional sense, JSON (JavaScript Object Notation) is widely used in Hardhat for configuration files and data interchange. Hardhat uses a JSON configuration file to set up project settings, networks, and compilers.

Here is an example of a Hardhat configuration file:

{
    "solidity": "0.8.0",
    "networks": {
        "hardhat": {
            "chainId": 1337
        }
    }
}

This JSON configuration specifies the Solidity version and network settings for the Hardhat environment.

Conclusion

Hardhat primarily supports Solidity for smart contract development, along with JavaScript and TypeScript for scripting and testing. Additionally, JSON is used for configuration purposes. This combination of languages makes Hardhat a versatile and powerful tool for Ethereum developers, enabling them to build, test, and deploy decentralized applications efficiently.