Working with types: Wrapper classes - Java test

Working with types: Wrapper classes - Java test

1) The wrapper classes are part of the which package, that is imported by default into all Java programs?

A) java.lang
B) java.awt
C) java.io
D) java.util
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2) Which defines a method called nextElement that is used to get the next element in a data structure that contains multiple elements?

A) Bitset
B) Vector
C) Stack
D) Enumeration
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3) Which defines the methods by which you can enumerate (obtain one at a time) the elements in a collection of objects?

A) Stack class
B) Bitset class
C) Enumeration interface
D) None of the above
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4) Which specifies the following two methods ?
boolean hasMoreElements()
Object nextElement()

A) Enumeration
B) Bitset
C) Vector
D) Stack
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5) Which method Returns an enumeration of the values contained in the dictionary?

A) Enumeration elements()
B) Enumeration keys()
C) Enumeration propertyNames()
D) None of the above
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6) Which method Returns an enumeration of the keys, This includes those keys found in the default property list, too?

A) Enumeration keys()
B) Enumeration elements()
C) Enumeration propertyNames()
D) Both A & B
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7) StringTokenizer implements the Enumeration interface?

A) True
B) False
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8) Which package does java provides in which it acts as an object -oriented wrapper around most common databases?

A) JDBC
B) ODBC
C) None of the above
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9) Filtered streams are simply wrappers around underlying input or output streams that transparently provide some extended level of functionality?

A) True
B) False
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10) Wrapper classes are not used to convert any data type into an object?

A) True
B) False
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11) Void it is not a wrapper class?

A) True
B) False
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12) The primitive data type values will be stored in ?

A) Heap Memory
B) Stack Memory
C) Both A & B
D) None of the above
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13) Which can be used as raw data for operations such as arithmetic, logical, etc?

A) Primitive data types
B) Wrapper classes
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14) The following two statements illustrate the difference between a

int x = 25;
Integer y = new Integer(33);

A) Primitive data types
B) primitive data type and an object of a wrapper class
C) Wrapper class
D) None of the above
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15) Which allow the caller to remove elements from the underlying collection during the iteration with well-defined semantics?

A) Enumeration
B) Iterator
C) None of the above
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16) Which method When implemented, it must return true while there are still more elements to extract, and false when all the elements have been enumerated?

A) Object nextElement( )
B) boolean hasMoreElements( )
C) Both A & B
D) None of the above
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