Record structs in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a record struct in C#?

A record struct is a value type that provides built-in features like immutability, value equality, and concise syntax for defining data containers, introduced in C# 10.

intermediate

How does a record struct differ from a regular struct?

A record struct automatically provides value-based equality, a concise syntax for defining properties, and supports with-expressions for copying with modifications, unlike regular structs which require manual implementation.

intermediate

Can a record struct be mutable or immutable?

By default, record structs are mutable, but you can make them immutable by declaring properties with only getters or using the readonly modifier.

beginner

What feature allows you to create a copy of a record struct with some properties changed?

The with expression lets you create a new record struct by copying an existing one and changing specified properties.

beginner

Write a simple example of a record struct with two properties: int X and int Y.

public record struct Point(int X, int Y);

Which of the following is true about record structs in C#?

A They are reference types with value equality.

B They are value types with built-in value equality.

C They cannot have properties.

D They do not support the with-expression.

Record structs are value types that provide built-in value equality and support with-expressions.

How do you declare a record struct named 'Point' with properties 'X' and 'Y'?

A struct Point record(int X, int Y);

B struct record Point { int X; int Y; }

C record Point struct(int X, int Y);

D record struct Point(int X, int Y);

The correct syntax is 'record struct Point(int X, int Y);' which declares a record struct with two properties.

What does the 'with' expression do for record structs?

A Creates a copy with some properties changed.

B Deletes the record struct instance.

C Converts the record struct to a class.

D Makes the record struct mutable.

The 'with' expression creates a new copy of the record struct with specified properties changed.

Are record structs mutable by default?

A No, they are immutable by default.

B They cannot be mutable.

C Yes, they are mutable by default.

D They are always readonly.

Record structs are mutable by default unless marked readonly or with immutable properties.

Which C# version introduced record structs?

A C# 10

B C# 8

C C# 9

D C# 7

Record structs were introduced in C# 10.

Explain what a record struct is and how it differs from a regular struct in C#.

Think about how record structs help with comparing and copying data.

Describe how you can create a copy of a record struct with one property changed.

Remember the keyword that starts with 'w' used for copying with changes.