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What state is a thread in when it is executing
An executing thread is in the running state.
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What Checkbox method allows you to tell if a Checkbox is checked
getState()
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Are true and false keywords
The values true and false are not keywords.
Sandhya.Kishan
- May 22nd, 2012
No true and false are not keywords but they can only be the return types of a boolean data type.
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Use of abstract class and interface
What is the exact use of abstract class and interface?
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If an object is garbage collected, can it become reachable again
Once an object is garbage collected, it ceases to exist. It can no longer become reachableagain.
Sandhya.Kishan
- May 22nd, 2012
An object reaches the garbage collection once it becomes unreachable and it cannot become reachable again.
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When is an object subject to garbage collection
An object is subject to garbage collection when it becomes unreachable to the program inwhich it is used.
Sandhya.Kishan
- May 24th, 2012
When an object becomes unreachable to the program in which it is being used then an object subjects to the garbage collection.
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What is the difference between a Scrollbar and a ScrollPane
A Scrollbar is a Component, but not a Container. A ScrollPane is a Container. AScrollPane handles itsown events and performs its own scrolling.
Sandhya.Kishan
- May 24th, 2012
*A scroll-bar is a component. *A scroll bar provides a convenient means for allowing a user to select from a range of values. *Scroll-bars can either be vertical or horizontal. *It has multiples compo...
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What is a void return type
A void return type indicates that a method does not return a value.
Sandhya.Kishan
- May 26th, 2012
If a function does not return any value then it is of void return type.
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What happens when you add a double value to a String
The result is a String object.
Sandhya.Kishan
- May 26th, 2012
When we add a double value to a string then the resulting value is a string object.
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Implicit objects of jsp are available in destroy() method or not?
Sandhya.Kishan
- May 30th, 2012
No the implicit objects of JSP are not available in destroy() method. The destroy method is invoked by the container when a JSP page is about to be destroyed.It can be overridden by a page author to p...
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What restrictions are placed on method overloading
Two methods may not have the same name and argument list but different return types.
Sandhya.Kishan
- May 30th, 2012
In method overloading
1.methods should have the same name.
2.The methods may or may not have return type and the return type may or may not be the same.
The signature should be different. -
What is the return type of a program's main() method
A program's main() method has a void return type.
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Name four Container classes
Window, Frame, Dialog, FileDialog, Panel, Applet, or ScrollPane
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What class allows you to read objects directly from a stream
The ObjectInputStream class supports the reading of objects from input streams.
Sandhya.Kishan
- May 30th, 2012
The class allows to read objects directly from a stream is the ObjectInputStream class.
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Which non-Unicode letter characters may be used as the first character of anidentifier
The non-Unicode letter characters $ and _ may appear as the first character of anidentifier
Sandhya.Kishan
- May 30th, 2012
Ampersand "$" is the non-unicode letter characters which can be used as the first character of an identifier.
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How can the Checkbox class be used to create a radio button
By associating Checkbox objects with a CheckboxGroup.
Sandhya.Kishan
- May 30th, 2012
Checkbox objects can be associated with a CheckboxGroup such that the checkbox class can be used to create a radio button.
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What class of exceptions are generated by the Java run-time system
The Java runtime system generates RuntimeException and Error exceptions.
Sandhya.Kishan
- May 30th, 2012
Error exceptions and run time exceptions are generated by the Java run-time system.
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Which class is the immediate superclass of the Container class
Component
Sandhya.Kishan
- May 30th, 2012
The immediate super class of the container class is java.awt.Compnoent
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What is the difference between a field variable and a local variable
A field variable is a variable that is declared as a member of a class. A local variable is avariable that isdeclared local to a method.
Sandhya.Kishan
- Jun 1st, 2012
1.A field variable is a variable which is declared as a member of a class where as a local variable is declared in a method which belongs to a class. 2.Field variables are alive as long as the instanc...
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How are this() and super() used with constructors
This() is used to invoke a constructor of the same class. super() is used to invoke asuperclass constructor.
Sandhya.Kishan
- Jun 1st, 2012
If we want to execute the constructor before executing the functionality of a method then we use this() constructor.This()refers the current constructor. When we want to invoke the constructor of the...
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