# C# Warnings and Errors
For F# see [[FSharp Warnings and Errors|F# Warnings and Errors]].
## Error and Warning Codes
- 0114 – hiding base implementation in child class
- 0162 – unreachable code (early returns)
- 0219 – a variable is assigned but its value is never used
- 1701 – reference version mismatch. A [[Binding Redirects|binding redirect]] is needed, or this error needs to be suppressed.
## Promoting Warnings into Errors
You can promote warnings into errors using the `WarningsAsErrors` property
```xml
<PropertyGroup>
<WarningsAsErrors>;NU1605; 0114</WarningsAsErrors>
</PropertyGroup>
```
## Disabling (suppressing) Warnings
Done with the `#pragma` directive locally in a file:
```csharp
#pragma warning disable 0649
#pragma warning restore 0649
```
Or, using a csproj property in the project or the Directory.Build.props file.
```xml
<PropertyGroup>
<NoWarn>1701;1702;0114</NoWarn>
</PropertyGroup>
```