Java Reference
In-Depth Information
Suppose the Air Filter object is stored at location 3472 and the Ball Joint object is stored at location 5768 .
Then the value of a would be 3472 , and the value of b would be 5768 . After the two objects have been created, we have
the situation shown in Figure 2-5 .
name: Air Filter
price: 8.75
name: Ball Joint
price: 29.95
3472
a
5768
b
Figure 2-5. After creation of two Part objects
Suppose we then assign a to c , like this:
Part c = a; // assign 3472 to c
This assigns the value 3472 to c ; in effect, c (as well as a ) now points to the Air Filter object. We can use either
variable to access the object. For instance, the following sets the price of the Air Filter object to 9.50 :
c.setPrice(9.50);
We have the situation shown in Figure 2-6 .
name: Air Filter
price: 9.50
3472
a
3472
c
Figure 2-6. After assigning a to c
If we now retrieve the price of object a with the following, the (new) price of Air Filter would be returned:
a.getPrice(); // returns the price 9.50
Suppose we write this statement:
c = b; // assign 5768 to c
c is assigned 5768 and now points to the Ball Joint object. It no longer points to Air Filter. We can use b or c
to access Ball Joint data. If we have the address of an object, we have all the information we need to manipulate
the object.
 
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