Method References to Instance Methods
To pass a reference to an instance method on a specific object, use the syntax: objRefName::methodName. This syntax is similar to that used for a static method, except that an object reference is used instead of a class name. The following program demonstrates a static method reference. In the program, notice that myOldMobile( ) and myNewMobile( ) are instance methods of MyMobile. Inside main( ), an instance of MyMobile called ‘my’ is created. This instance is used to create the method reference to myOldMobile( ) and myNewMobile( ) in the call to ‘my’.
Program
interface Mobile {
String myMobile();
}
class MyMobile {
String myOldMobile() {
return "Old : Samsung Galaxy S6";
}
String myNewMobile() {
return "New : Samsung Galaxy S9";
}
}
class Javaapp {
static void showMyMobile(Mobile mo) {
System.out.println(mo.myMobile());
}
public static void main(String[] args) {
MyMobile my = new MyMobile();
showMyMobile(my::myOldMobile);
showMyMobile(my::myNewMobile);
}
}