Kwenye Dart, enum ni kama ilivyo katika lugha nyingine nyingi. Ni njia ya kutengeneza seti ya thamani zinazojulikana, na kila mojawapo inawakilisha thamani maalum. Enum hutengenezwa kwa kutumia keyword enum.
Hapa kuna mfano wa jinsi enum inavyofanya kazi katika Dart:
enum gari {
toyota,
BMW,
basi,
bugati
}
void main() {
gari mycar = gari.toyota;
switch (mycar) {
case gari.toyota:
print("Gari ni Toyota");
break;
case gari.bugati:
print("Gari ni bugati");
break;
case gari.BMW:
print("Gari ni BMW");
break;
case gari.basi:
print("Gari ni basi");
}
}
Sifa za enum
- Zote zina value ambazo ni constant value walau moja
- Enum huwekwa nje ya class na sio ndani ya class
- Inaweza kuhifadhi constant value nyingi
Angalia mfano mwingine hapa chini
enum Gender { Male, Female, Other }
class Person {
// Properties
String? firstName;
String? lastName;
Gender? gender;
// Constructor
Person(this.firstName, this.lastName, this.gender);
// display() method
void display() {
print("First Name: $firstName");
print("Last Name: $lastName");
print("Gender: $gender");
}
}
void main() {
Person p1 = Person("John", "Doe", Gender.Male);
p1.display();
Person p2 = Person("Menuka", "Sharma", Gender.Female);
p2.display();
}
Kwa kutumia for in loop unaweza ku print member wote kwenye list
enum Days { Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday }
void main() {
// Days.values: It returns all the values of the enum.
for (Days day in Days.values) {
print(day);
}
}
Faida za kutumia enum
- Hutumika kuweka set zenye value ambazo ni constant
- Code ni rahisi kusomeka
- Ni rahisi kutumia code zaidi ya mara moja.
Mwisho:
Katika somo linalofuata tutakwend akujifunza kuhusu abstract class.
