In C#, a const keyword is used to declare constant fields and constant local. The value of the constant field is the same throughout the program or in other words, once the constant field is assigned the value of this field is not be changed. In C#, constant fields and locals are not variables, a constant is a number, string, null reference, boolean values.
The value of myvar: 10 The value of str: GeeksforGeeks
In C#, you can use a readonly keyword to declare a readonly variable. This readonly keyword shows that you can assign the variable only when you declare a variable or in a constructor of the same class in which it is declared.
Display value of myvar1 100, and myvar2 200
ReadOnly Vs Const Keyword
|ReadOnly Keyword||Const Keyword|
|In C#, readonly fields can be created using readonly keyword||In C#, constant fields are created using const keyword.|
|ReadOnly is a runtime constant.||Const is a compile time constant.|
|The value of readonly field can be changed.||The value of the const field can not be changed.|
|It cannot be declared inside the method.||It can be declared inside the method.|
|In readonly fields, we can assign values in declaration and in the contructor part.||In const fields, we can only assign values in declaration part.|
|It can be used with static modifiers.||It cannot be used with static modifiers.|