final keywords in Dart are used to declare variables that cannot be reassigned after they have been initialized. However, there is a subtle difference between the two keywords:
constkeyword is used to declare variables that are compile-time constants. This means that the value of a
constvariable must be known at compile time and cannot be changed during runtime. In addition,
constvariables are implicitly
finaland must be set to a value that is also a
const, such as a string, number, or constant expression.
finalkeyword is used to declare variables that are runtime constants. This means that the value of a
finalvariable can be set at runtime, but cannot be changed after it has been initialized. Unlike
finalvariables can be set to values that are not
const, such as the result of a function call or a user-input value.
In general, you should use the
const keyword when you need to declare a value that must be constant at compile time and the
final keyword when you need to declare a value that can be set at runtime but cannot be changed after it has been initialized. If you are not sure which keyword to use, it is usually safe to use