use JFrame before it is constructed

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Martijn Mulder - 12 Feb 2006 01:52 GMT

Is it safe to use JFrame before the constructor is invoked as in this code
sample:

class MyClass
{
javax.swing.JFrame jframe=new javax.swing.JFrame("MyFrame");
javax.swing.JDialog jdialog=new javax.swing.JDialog(jframe,"MyDialog");
MyClass(){}
}

Thank you

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IchBin - 12 Feb 2006 02:49 GMT

> Is it safe to use JFrame before the constructor is invoked as in this code
> sample:
[quoted text clipped - 7 lines]
>
> Thank you

Sure..

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Thanks in Advance...
IchBin, Pocono Lake, Pa, USA
http://weconsultants.servebeer.com/JHackerAppManager
__________________________________________________________________________

'If there is one, Knowledge is the "Fountain of Youth"'
-William E. Taylor, Regular Guy (1952-)

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Chris Smith - 12 Feb 2006 03:55 GMT

> Is it safe to use JFrame before the constructor is invoked as in this code
> sample:
[quoted text clipped - 5 lines]
> MyClass(){}
> }

Your code is safe. Note that you are NOT using a JFrame before it is
constructed, and that's why it's safe. By the time the initialization
expression got jdialog has finished, the variable jframe is already
completely initialized.

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Martijn Mulder - 12 Feb 2006 19:13 GMT

>> Is it safe to use JFrame before the constructor is invoked as in this
>> code
[quoted text clipped - 6 lines]
>> MyClass(){}
>> }

> Your code is safe. Note that you are NOT using a JFrame before it is
> constructed, and that's why it's safe. By the time the initialization
> expression got jdialog has finished, the variable jframe is already
> completely initialized.

I see. And is this safe?

class MyClass extends javax.swing.JFrame
{
javax.swing.JDialog jdialog=new javax.swing.JDialog(this,"MyDialog");
MyClass(){super("MyFrame");}
}

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Thomas A. Russ - 13 Feb 2006 18:48 GMT

> I see. And is this safe?

Yes, at least once the accidental change of case gets corrected.
See the Java Language Reference, section 8.3.2.2

"this" can be used in the initializers of class instance variables.

> Class Myclass Extends Javax.Swing.Jframe
> {
> Javax.Swing.Jdialog Jdialog=New Javax.Swing.Jdialog(This,"Mydialog");
> Myclass(){Super("Myframe");}
> }

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Thomas A. Russ, USC/Information Sciences Institute

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use JFrame before it is constructed

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