Question How to fix error cs0246

do not really understand what I am suppose to do.

below is my programming.

 

Assets\playerScripts.cs(31,30): error CS0246: The type or namespace name 'MonoBehaviour' could not be found (are you missing a using directive or an assembly reference?)

 

In the playerScript.cs the approperiate using is probably missing at the start of the file:

Code (CSharp):

1. using UnityEngine;

In C# all classes, interfaces, enums, etc. are part of the namespaces. You have to tell the compilter to use these namespaces defined with "using".
Other option is to specify the namespace right before the class like

Code (CSharp):

1. UnityEngine.MonoBehavior

See also https://docs.microsoft.com/en-us/dotnet/csharp/fundamentals/types/namespaces

 

Is this a homework assignment? This isn't Unity code, there are 3 classes in one file.