Read-only and write-only properties in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a read-only property in C#?

A read-only property is a property that allows you to get (read) its value but not set (write) it. It has a getter but no setter.

beginner

What is a write-only property in C#?

A write-only property is a property that allows you to set (write) its value but not get (read) it. It has a setter but no getter.

beginner

How do you declare a read-only property in C#?

You declare a read-only property by providing only the get accessor and omitting the set accessor. Example: <br>

public int Age { get; }

intermediate

Can a property be both read-only and write-only at the same time?

No, a property cannot be both read-only and write-only simultaneously because it would mean you can neither read nor write it. It must have at least one accessor.

intermediate

Why would you use a write-only property?

You use a write-only property to allow setting a value without allowing it to be read back. This can be useful for sensitive data like passwords where you want to accept input but not expose the value.

Which accessor(s) does a read-only property have?

A Only get

B Only set

C Both get and set

D Neither get nor set

A read-only property has only the get accessor to allow reading the value.

What happens if you try to read a write-only property?

A You get the property's value

B The property returns null

C You get a compile-time error

D The program crashes at runtime

Trying to read a write-only property causes a compile-time error because there is no get accessor.

How do you declare a write-only property in C#?

A Provide both get and set accessors

B Provide only the get accessor

C Provide neither accessor

D Provide only the set accessor

A write-only property has only the set accessor to allow writing the value.

Why might you want a property to be read-only?

A To make the property private

B To prevent external code from changing its value

C To allow both reading and writing

D To prevent reading the value

Read-only properties allow reading but prevent external code from changing the value.

Which of these is a valid read-only property declaration?

A public int Value { get; }

B public int Value { set; }

C public int Value { get; set; }

D public int Value { }

A read-only property has only the get accessor, like 'public int Value { get; }'.

Explain how to create a read-only property in C# and why you might use it.

Think about properties that should not be changed after creation.

Describe a scenario where a write-only property is useful and how to declare it.

Consider when you want to accept input but not reveal it.