C# Compiler Error
CS0077 – The as operator must be used with a reference type or nullable type (‘int’ is a non-nullable value type).
Reason for the Error
You will receive this error when you use as operator and pass a value type. For example, try compiling the below code.
public class DeveloperPublish { public static void Main() { float j = 2.0f; var result = j as int; } }
C#
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public class DeveloperPublish
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{
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public static void Main()
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{
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float j = 2.0f;
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var result = j as int;
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}
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}
You will receive the below error since you are using the as operator and passing a int as type. The ‘as’ operator in C# can only be passed a reference type or nullable value types in C#.
Error CS0077 The as operator must be used with a reference type or nullable type (‘int’ is a non-nullable value type)

Solution
To fix the error CS0077 in C#, you will need to avoid passing the value type and use reference types when you are using the ‘as’ operator.