Answer
An extension method is a static method that can be called with instance-method syntax on its receiver type. • Traditional extension methods use this on the first parameter in a non-nested static class. • They do not modify the extended type or gain access to private members. • A real instance member takes precedence over an extension method with the same applicable signature.
💡 C# Example
public static class StringExtensions
{
public static bool HasText(this string? value) => !string.IsNullOrWhiteSpace(value);
}
⚡ Quick Revision
Extension methods add call syntax, not actual members or private access.