Why we can't instantiated System class.
Hi All,
I can't undersatnd what type of class is "System". We can't instantiated system class but we can use it like a Static class.
There are number of classes like that. You don't
instantiate them because you don't need to.Objects
have state and behavior. State is captured inmember
variables. None of the functionality the Systemclass
provides requires an object to be instantiated and
maintain state in member variables. It's pure
behavior.I beg to differ. Given he fact that it has attributes
(e.g. in, out and err), it does have a state...They're static attributes, so no instance (if one existed) would have its own state that would potentially distinguish it from other instances. That's what I was talking about.
I, personally, think that static classes are rather
bad OO (it's objects doing the work, not classes),
but singletons are too burdensome to create.You mean uninstantiable classes with only static methods? (System is not a static class. Only nested classes can be static.)
If your goal is to write pure OO, then, yeah, they might be bad. But then I don't think "perfect OO" is a particularly important or useful goal. Tool for the job and all that.
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Hi people!
I'm studying for a SCJP 6, and i encountered this question that i can figure it out but i don't find any official information of my guess.
I have the following code:
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public static void main(String[] args) {
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Regards,
Christian Vielmacvielma wrote:
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Regards
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double s1=0;
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double sumEven=0;
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s=(sumEven + sumOdd + (x2 * k * Math.cos(x2-a))) * (h/3);
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new Application();first bug: in initComponents() you say
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JPanel p1 = null;
GPanel p2 = null; // looks like another class name !
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