Accessing Objects o Referencing the object s data objectRefvar data e. g, my Circle radius o Invoking the object s method objectRefvar methodname(arguments) e. g. my Circle. findAreao Introduction to Java Programming, revised by Dai-kaiyu
Liang,Introduction to Java Programming,revised by Dai-kaiyu 16 Accessing Objects ⚫Referencing the object’s data: objectRefVar.data e.g., myCircle.radius ⚫Invoking the object’s method: objectRefVar.methodName(arguments) e.g., myCircle.findArea()
Example 6. 1 Using Objects o Objective: Demonstrate creating objects accessing data, and using methods Testsimplecircle RI un Introduction to Java Programming, revised by Dai-kaiyu
Liang,Introduction to Java Programming,revised by Dai-kaiyu 17 Example 6.1 Using Objects ⚫Objective: Demonstrate creating objects, accessing data, and using methods. TestSimpleCircle Run
Tr ace code Declare my Circle Circle my Circle=new Circle(5.0) myclrcle no value SCircle your Circle=new Circle your Circle radius= 100 Introduction to Java Programming, revised by Dai-kaiyu
Liang,Introduction to Java Programming,revised by Dai-kaiyu 18 Trace Code Circle myCircle = new Circle(5.0); SCircle yourCircle = new Circle(); yourCircle.radius = 100; Declare myCircle myCircle no value
Trace Code cont Circle my Circle =new Circle(5.0) myclrcle no value Circle your Circle= new Circle your Circle radius= 100 Circle radius: 5.0 Create a circle Introduction to Java Programming, revised by Dai-kaiyu
Liang,Introduction to Java Programming,revised by Dai-kaiyu 19 Trace Code, cont. Circle myCircle = new Circle(5.0); Circle yourCircle = new Circle(); yourCircle.radius = 100; : Circle radius: 5.0 myCircle no value Create a circle
Trace Code cont Circle my Circle=new Circle(5.0) mycircle reference value Circle your Circle= new Circle your Circle radius= 100 Assign object reference Circle to my circle radius: 5.0 Introduction to Java Programming, revised by Dai-kaiyu
Liang,Introduction to Java Programming,revised by Dai-kaiyu 20 Trace Code, cont. Circle myCircle = new Circle(5.0); Circle yourCircle = new Circle(); yourCircle.radius = 100; : Circle radius: 5.0 myCircle reference value Assign object reference to myCircle