What is the difference between const and read-only in C#?

Question

Aryan Kumar · Answer

The const and readonly keywords in C# are both used to declare constants. However, there are some key differences between the two keywords.
const constants are compile-time constants, while
readonly constants are runtime constants. This means that the value of a
const constant is known at compile time, while the value of a 
readonly constant can be changed at runtime.const constants must be initialized when they are declared, while
readonly constants can be initialized later. This means that you cannot declare a
const constant without initializing it, while you can declare a 
readonly constant and initialize it later.const constants are implicitly static, while
readonly constants can be static or non-static. This means that a
const constant is always a static member of a class, while a readonly constant can be a static member or an instance member of a class.
In general, you should use const constants when the value of the constant is known at compile time and you do not need to be able to change the value at runtime. You should use
readonly constants when the value of the constant can be changed at runtime, or when you need to be able to declare a constant that is not a static member of a class.
Here is a table that summarizes the key differences between const and
readonly:
Feature
const
readonly
Compile-time constant
Yes
No
Initialization
Must be initialized when declared
Can be initialized later
Static
Implicitly static
Can be static or non-static
When to use
When the value of the constant is known at compile time and you do not need to be able to change the value at runtime
When the value of the constant can be changed at runtime, or when you need to be able to declare a constant that is not a static member of a class

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What is the difference between const and read-only in C#?

Steilla Mitchel

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Feature	`const`	`readonly`
Compile-time constant	Yes	No
Initialization	Must be initialized when declared	Can be initialized later
Static	Implicitly static	Can be static or non-static
When to use	When the value of the constant is known at compile time and you do not need to be able to change the value at runtime	When the value of the constant can be changed at runtime, or when you need to be able to declare a constant that is not a static member of a class