C# value and reference types, nullable types, strings, control flow, methods, arrays and the .NET type system.
39 cards · basic cards · AI-written, checked twice. Edit anything.
- What is a value type in C#?
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A type whose instances are stored directly on the stack and contain their actual data.- Where are value types stored in memory?
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On the stack.- What is boxing in C#?
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Converting a value type to an object reference type, allocating it on the heap.- What is unboxing in C#?
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Extracting a value type from a boxed object, converting it back to its value form.- What does struct keyword declare?
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A value type that can contain methods, properties, and fields.- What is the main difference between struct and class?
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Struct is a value type (stack), class is a reference type (heap).- Name three built-in value types in C#.
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int, double, bool (or byte, decimal, char, long, etc.)- Do value type fields have default values?
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Yes, all fields are initialized to their default value (0, false, etc.) automatically.- What is a reference type in C#?
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A type whose instances store a reference to data on the heap, not the data itself.- Where are reference types stored in memory?
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On the heap, with a reference stored on the stack.- What does class keyword declare?
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A reference type that can contain methods, properties, fields, and other members.- What is the difference between passing by value and by reference?
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By value: a copy is passed; by reference: the original variable is passed and changes reflect outside.- What does the new keyword do?
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Allocates memory on the heap and calls a constructor for a reference type.- What is null in C#?
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A special value indicating a reference type variable does not point to any object.- What is the syntax for a nullable type?
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Type followed by a question mark, e.g. int?, double?, string?
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