Static variable ni nini?
Hii ni variable ambayo inaweza kutumika kwenye class yote. Hii hutumika kuifadhi data ambazo zipo kwenye class. Na hutengenezwa kwa ytuma keyword static. Unapotaka kutumia static variable huna haja ya kutengeneza object.
Mfano:
class gari {
// Static variable
static String jina = "toyota";
}
Ili uweze kuitumia static variable utatumia jina la class na jina la hiyo static variable kama tulivyozoea.
class gari {
// Static variable
static String jina = "toyota";
}
void main(){
String waf = gari.jina;
print(waf);
}
Angalia mfano mwingine hapo chini.
class Student {
int id;
String name;
static String schoolName = "ABC School";
Student(this.id, this.name);
void display() {
print("Id: ${this.id}");
print("Name: ${this.name}");
print("School Name: ${Student.schoolName}");
}
}
void main() {
Student s1 = new Student(1, "John");
s1.display();
Student s2 = new Student(2, "Smith");
s2.display();
}
Static variable inaweza pia ikawa ni function. Hapa kuna program kwa ajili ya kutengeneza password. Yenyewe inatumia static variable ambayo ni function.
import 'dart:math';
class PasswordGenerator {
static String generateRandomPassword() {
List<String> allalphabets = 'abcdefghijklmnopqrstuvwxyz'.split('');
List<int> numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
List<String> specialCharacters = ["@", "#", "%", "&", "*"];
List<String> password = [];
for (int i = 0; i < 5; i++) {
password.add(allalphabets[Random().nextInt(allalphabets.length)]);
password.add(numbers[Random().nextInt(numbers.length)].toString());
password
.add(specialCharacters[Random().nextInt(specialCharacters.length)]);
}
return password.join();
}
}
void main() {
print(PasswordGenerator.generateRandomPassword());
}
Mwisho:
Katika somo linalofuata tutakwenda kujifunza kuhusu enum.
