How to Set the Compiler Version in a Solidity Smart Contract

Solidity developers must specify a compiler version for their smart contracts. Ensuring compatibility with the compiler helps avoid compilation errors when using features or syntax available only in specific versions.

The version can be specified as a single version, or a range of versions, with the pragma compiler directive. It’s typically the first line of code under the license identifier.

For example,

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;

Here, we instruct the compiler to use the most recent version of Solidity that is backward compatible with version 0.8.17.

Or to declare a version range,

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0 <=0.8.17;

Note: Using a version range is only recommended for projects that must maintain compatibility with older compiler versions. For new projects, it’s best to use the most recent version of the Solidity compiler available.