> **Warning**: Unless a concrete version is specified in the [`global.json`](https://learn.microsoft.com/en-us/dotnet/core/tools/global-json) file, **_the latest .NET version installed on the runner (including preinstalled versions) will be used [by default](https://learn.microsoft.com/en-us/dotnet/core/versions/selection#the-sdk-uses-the-latest-installed-version)_**. Please refer to the [documentation](https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners#supported-software) for the currently preinstalled .NET SDK versions.
The `dotnet-version` input supports following syntax:
- **A.B.C** (e.g 6.0.400, 7.0.100-preview.7.22377.5) - installs exact version of .NET SDK
- **A.B** or **A.B.x** (e.g. 3.1, 3.1.x) - installs the latest patch version of .NET SDK on the channel `3.1`, including prerelease versions (preview, rc)
- **A** or **A.x** (e.g. 3, 3.x) - installs the latest minor version of the specified major tag, including prerelease versions (preview, rc)
## Using the `dotnet-quality` input
This input sets up the action to install the latest build of the specified quality in the channel. The possible values of `dotnet-quality` are: **daily**, **signed**, **validated**, **preview**, **ga**.
> **Note**: `dotnet-quality` input can be used only with .NET SDK version in 'A.B', 'A.B.x', 'A' and 'A.x' formats where the major version is higher than 5. In other cases, `dotnet-quality` input will be ignored.
`setup-dotnet` action can read .NET SDK version from a `global.json` file. Input `global-json-file` is used for specifying the path to the `global.json`. If the file that was supplied to `global-json-file` input doesn't exist, the action will fail with error.
>**Note**: In case both `dotnet-version` and `global-json-file` inputs are used, versions from both inputs will be installed.
The action has a built-in functionality for caching and restoring dependencies. It uses [toolkit/cache](https://github.com/actions/toolkit/tree/main/packages/cache) under the hood for caching global packages data but requires less configuration settings. The `cache` input is optional, and caching is turned off by default.
The action searches for [NuGet Lock files](https://learn.microsoft.com/nuget/consume-packages/package-references-in-project-files#locking-dependencies) (`**/packages.lock.json`) in the repository, calculates their hash and uses it as a part of the cache key. If lock file does not exist, caching will not be enabled.
> **Warning:** Caching NuGet packages is available since .NET SDK 2.1.500 and 2.2.100 as the NuGet lock file [is available](https://learn.microsoft.com/nuget/consume-packages/package-references-in-project-files#locking-dependencies) only for NuGet 4.9 and above.
**Note:** Use [`NUGET_PACKAGES`](https://learn.microsoft.com/nuget/reference/cli-reference/cli-ref-environment-variables) environment variable if available. Some action runners already has huge libraries. (ex. Xamarin)
Using `setup-dotnet` it's possible to use [matrix syntax](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstrategymatrix) to install several versions of .NET SDK:
>**Note**: Unless a concrete version is specified in the [`global.json`](https://learn.microsoft.com/en-us/dotnet/core/tools/global-json) file, the latest .NET version installed on the runner (including preinstalled versions) will be used [by default](https://learn.microsoft.com/en-us/dotnet/core/versions/selection#the-sdk-uses-the-latest-installed-version). To control this behavior you may want to use temporary `global.json` files:
**Matrix testing with temporary global.json creation**
When the `dotnet-version` input is used along with the `global-json-file` input, the `dotnet-version` output contains the version resolved from the `global.json`.
Some environment variables may be necessary for your particular case or to improve logging. Some examples are listed below, but the full list with complete details can be found here: https://docs.microsoft.com/en-us/dotnet/core/tools/dotnet-environment-variables
| NUGET_PACKAGES |Configures a path to the [NuGet `global-packages` folder](https://learn.microsoft.com/nuget/consume-packages/managing-the-global-packages-and-cache-folders)|*default value for each OS* |