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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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If a method is declared as protected, where may the method be accessed
A protected method may only be accessed by classes or interfaces of the same package orby subclasses ofthe class in which it is declared.
Sandhya.Kishan
- Jul 25th, 2012
The classes or interfaces in which the method is declared can access the protected method.It can also be access within a class through member function and outside a class through public interface.
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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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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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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 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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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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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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Under what conditions is an object's finalize() method invoked by the garbagecollector
The garbage collector invokes an object's finalize() method when it detects that the objecthas becomeunreachable.
Sandhya.Kishan
- Jun 11th, 2012
When an object has no references then it reaches its unreachable condition and under this condition the finalize() method is invoked by the garbage collector.
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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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What is the relationship between a method's throws clause and the exceptionsthat can bethrown during the method's execution
A method's throws clause must declare any checked exceptions that are not caught withinthe body of themethod.
Sandhya.Kishan
- Jul 31st, 2012
Any checked exceptions that are not caught within the body of the method must declare in a methods throws clause.
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Why are the methods of the Math class static
So they can be invoked as if they are a mathematical code library.
Sandhya.Kishan
- Jun 1st, 2012
Math class contains methods used for mathematical calculations since they do not depend on instance data to perform their job and hence they are static.
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What Checkbox method allows you to tell if a Checkbox is checked
getState()
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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 are the legal operands of the instanceof operator
The left operand is an object reference or null value and the right operand is a class,interface, or array type.
Sandhya.Kishan
- Jul 23rd, 2012
The legal operands of instance of operator are
1. Left operand which is an object reference.
2. Right operand which can be a class or an interface.
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How are the elements of a GridLayout organized
The elements of a GridBad layout are of equal size and are laid out using the squares of agrid.
Sandhya.Kishan
- Jun 4th, 2012
The elements of a gridlayout are organized depending on the size and equal size are laid out using the squares of a grid.
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What an I/O filter
An I/O filter is an object that reads from one stream and writes to another, usuallyaltering the data in someway as it is passed from one stream to another.
Sandhya.Kishan
- Jul 31st, 2012
To read from one stream and then to write on other stream we use i/o filter.
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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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