Difference between reference variable and object ?

I am getting confused with reference variable and object ?
1. int a; // is a variable
2. Car c = new Car(); // is a object of car type
Suggest me what are the difference between the two.....

jverd wrote:
Shelby wrote:
Something about an interned string literal?_
I remember something from class about the way Java treats strings that contain the same data. yawmark
posted a link for me that cleared up my confusion. thanks yawmark.
>>
Can you actually point back to the original reference?Not clear what you're asking here. Nothing points to references. References point to objects.
Goodness, correct wording is as important as getting the syntax right, isn't it? ;-} What I was trying to ask is if it is possible to point back to the same String once you change the pointer on the variable?
And you answered my question succintly with the rest of your post. thanks jverd
>
String str = "abc";
str = null;'At this point, we've lost the reference to the original String object. However, at runtime, the VM will still be maintaining it in the constant pool. For any non-constant-pooled object, as we're writing our code, we'd have no way to refer to that object again. In this case, we are able to refer to the same object later in our code by simply using the same string literal. "abc" elsewhere in our code will cause the VM to give us a reference to that same pooled String. Same goes for Integer, etc. in the range -128..127.
However, it's not good design to rely on this. If your design requires you to later point to "the same object" (as opposed to any object of a compatible type and holding the same contents), then you should explicitly maintain a reference to it. In the case of Strings, you really shouldn't care whether it's the same object or not. All you care about is the character sequence that defines the String's state.

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Chilly Charly (aka CC)
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Race condition.vi ‏9 KB
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