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1.1 vs 1.2 Certification & What was Sun thinking?

 
Greenhorn
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Hi,
Two questions:
1) Whats the main difference between the 1.1 Certification exam and 1.2? I've been studying a book I purchased last year for Java 1.1 Certification and hope there isn't too much more to add for Java 2. As long as I avoid event handling in the 1.02 model, this isn't wasted effort I hope....?
and
2) Why in the world does Java work like this:
"An object reference determines which variable is accessed (parent vs subclass) and the underlying object determines which method is invoked (again parent vs subclass)". Why did Sun choose to do it this way? Isn't that inconsistent treatment of a class hierarchy?
Regards,
Steven
 
Greenhorn
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In 1.2 there have been alot of bugs fixed from a certification view yes it is alot changes than 1.1. Threads, event modeling, io... alot of differences.
To your second question : No comment.
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SCJP 2, MCP, CCNA
http://java.ditmas.net
 
Ranch Hand
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Hello s6384365,
Sooner or later, you are gonna have any Sheriff or Bartender of Javaranch tell you to change your username according to the stipulated norms. So, why don't you take the lead?
Regards
Shyam

[This message has been edited by Shyamsundar Gururaj (edited September 16, 2001).]
 
Ranch Hand
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For question 2;
"Why did Sun choose to do it this way? Isn't that inconsistent treatment of a class hierarchy?"

s6384365, as a programmer we don't want class hierarchy, we want inheritance, and objects themself knew which method should be used
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Have you tried this Mock Exam Testing Engin yet?
www.geocities.com/pei4nan/index.html
 
s6384365
Greenhorn
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nan sh,
I don't understand... Why if you have a class hierarchy and instantiate an object, refering to it as its superclass, is the method from the subclass used whereas the variables from the superclass get used? Shouldn't they come from either one or the other?
 
Author and all-around good cowpoke
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Variable references are calculated at compile time. Therefore the type of the reference determines which variable will be used.
Method calls are calculated dynamically at run time. Therefore they depend on the actual type of the object referred to.
Bill
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arch rival
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The differences between the 1.x cert and 1.2 (Java2 are very small). As you spotted, the event model is different, plus the 1.2 exam covers the Collection classes. I have forgotten the other minor differences but they are fairly minior. My tutorial at least mentions all the topics on the exam and if I don't mention it it almost certainly isn't on the exam.
Marcus
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nan sh
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s6384365,
I think your question is more about Java, its about Object Orient.
My understanding is that in the same class hierarchy you want different classes behavior different, that is method. And you have to have some status always the same to distinguish with other different class hierarchy, that is variables. subclass(child class) may have more status(variables) but you must have what your parent has, otherwise you are not their child.
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Have you tried this Mock Exam Testing Engine yet? www.geocities.com/pei4nan/index.html
[This message has been edited by nan sh (edited September 13, 2001).]
 
s6384365
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Hi Guys,
Regarding referencing a class with the type of its superclass: Intuitively it just seems to make more sense that the methods AND instance variables should both come from the same level in the hierarchy.
William, given what you said, wouldn't it then be most consistent if the parent class then supplies the variables and methods instead of just the variables? After all, this can be determined at compile time...

Regards,
Steven
p.s. How do I change my username if this is something thats contrary to Java Ranch's standards? Create a new account?
 
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Hi s6384365
Yup. Read the JavaRanch Name Policy first and then just re-register.
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Jane Griscti
Sun Certified Programmer for the Java� 2 Platform
 
With a little knowledge, a cast iron skillet is non-stick and lasts a lifetime.
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