The final keyword in Dart, which is also used in Flutter (since Flutter is built using Dart), is used to create a variable that can be set only once. This means that the value of a final variable can be assigned at runtime, but once it is assigned, it cannot be changed.

• Immutable State: Using final helps in creating immutable state which is beneficial for performance and avoiding bugs related to state changes.
• Constructor Initialization: final variables are often used with required parameters in constructors to ensure they are set during object creation.
• final is used for variables that are assigned once and do not change thereafter.
• It is commonly used in Flutter for widget properties to enforce immutability.
• final variables are initialized at runtime, unlike const which must be initialized at compile time.
• It helps in maintaining a predictable and consistent state within your application.

void main() { // Final variable example final name = 'Alice'; // 'name' is initialized only once // name = 'Bob'; // This will cause an error

final int age; age = 30; // 'age' is assigned only once // age = 31; // This will cause an error

print(name); // Output: Alice print(age); // Output: 30 }

When final is used with objects, the reference to the object is final, but the properties of the object can still be modified if they are not declared as final.

class Person { String name; Person(this.name); }

void main() { final person = Person('Alice'); person.name = 'Bob'; // Allowed: modifying a property // person = Person('Charlie'); // Not allowed: reassigning the final variable

print(person.name); // Output: Bob }