int approximation = (int) height;

Week 6: Methods of OO Programming/11A. TYPE Conversions/CASTING+++

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+As the type of a variable affects which features of an object can be referenced through it, 
+it's necessary to be able to change the type of the reference. 
+This is done through EXPLICIT TYPE CASTING. 
+We have previously used type casting, for example, when converting floating point numbers to integers:
+
+double height = 175.25;
+int approximation = (int) height;
+
+
+
+
+
+ 
+
+As previously noted, when class "Student" inherits from class "Person", a "Person"-type variable can be assigned a reference to a "Student" object. 
+However, this restricts the operations that can be used to those defined in the "Person" class. 
+Since the object is of type "Student", we can perform a type casting if necessary.
+
+After the type casting, the properties defined in the "Student" class are available:
+
+Person person = new Student("Oliver Student", "[email protected]", 14);
+
+// Through the variable 'person', we cannot now request study credits,
+// as the class has not defined the method. 
+// So let's do
+// 'type casting'
+// FROM 'Person' class to 'Student' class
+Student oliver = (Student) person;
+
+// approach 1 - BEST (less confusing)
+System.out.println("Oliver's study credits: " + oliver.getStudyCredits());
+
+// approach 2
+// this also works, but it's starting to be quite a confusing line
+System.out.println("Oliver's study credits: " + ((Student) person).getStudyCredits());
+ 
+
+
+
+
+
+If we have an object created from the "Student" class and a "Student"-type variable, 
+and we want to refer to the object with a "Person"-type variable, no type casting is needed. 
+This is because all students are people, but only some people are students:
+
+Student oliver = new Student("Oliver", "12354", 123);
+
+// This is OK WITHOUT TYPE CASTING, because all
+// Students are Persons
+Person oliverAsPerson = oliver;
+
+// This is also the same reason
+Object oliverAsObject = oliver;
+
+// VS
+// The other way around requires conversion
+Student oliver2 = (Student) oliverAsPerson;
+Person oliverAsPerson2 = (Person) oliverAsObject;
+
+