trait:
trait允许:
一个简单的例子:
class Example {
static void main(String[] args) {
Student st = new Student();
st.StudentID = 1;
st.Marks1 = 10;
println(st.DisplayMarks());
}
}
trait Marks {
void DisplayMarks() {
println("Display Marks");
}
}
class Student implements Marks {
int StudentID
int Marks1;
}
Trait可以实现接口:
class Example {
static void main(String[] args) {
Student st = new Student();
st.StudentID = 1;
st.Marks1 = 10;
println(st.DisplayMarks());
println(st.DisplayTotal());
}
}
interface Total {
void DisplayTotal()
}
trait Marks implements Total {
void DisplayMarks() {
println("Display Marks");
}
void DisplayTotal() {
println("Display Total");
}
}
class Student implements Marks {
int StudentID
int Marks1;
}
特征可以定义属性。
class Example {
static void main(String[] args) {
Student st = new Student();
st.StudentID = 1;
println(st.DisplayMarks());
println(st.DisplayTotal());
}
interface Total {
void DisplayTotal()
}
trait Marks implements Total {
int Marks1;
void DisplayMarks() {
this.Marks1 = 10;
println(this.Marks1);
}
void DisplayTotal() {
println("Display Total");
}
}
class Student implements Marks {
int StudentID
}
}
特征可以用于以受控的方式实现多重继承。 以下例子Student类实现了两个特征。由于Student类扩展了这两个特征,它能够访问这两种方法,DisplayMarks和DisplayTotal:
class Example {
static void main(String[] args) {
Student st = new Student();
st.StudentID = 1;
println(st.DisplayMarks());
println(st.DisplayTotal());
}
}
trait Marks {
void DisplayMarks() {
println("Marks1");
}
}
trait Total {
void DisplayTotal() {
println("Total");
}
}
class Student implements Marks,Total {
int StudentID
}
通过extends特征可以扩展特征:
class Example {
static void main(String[] args) {
Student st = new Student();
st.StudentID = 1;
println(st.DisplayMarks());
}
}
trait Marks {
void DisplayMarks() {
println("Marks1");
}
}
trait Total extends Marks {
void DisplayMarks() {
println("Total");
}
}
class Student implements Total {
int StudentID
}