JAVA COLLECTIONS 1.1

11. What is the Collection interface? The Collection interface provides support for the implementation of a mathematical bag - an unordered collection of objects that may contain duplicates.             12. What is the Set interface? The Set interface provides methods for accessing the elements of a finite mathematical set. Sets do not allow duplicate elements.             13. What...

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JAVA COLLECTIONS 1.0

1. What is the Collections API? The Collections API is a set of classes and interfaces that support operations on collections of objects.             2. What is the List interface? The List interface provides support for ordered collections of objects.             3. What is the Vector class? The Vector class provides the capability to implement a growable array of objects.  ...

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HCL & HP Java/J2EE Technical question Set 1.13

131. What are three ways in which a thread can enter the waiting state?             A thread can enter the waiting state by invoking its sleep() method, by blocking on I/O, by unsuccessfully attempting to acquire an object’s lock, or by invoking an object’s wait() method. It can also enter the waiting state by invoking its (deprecated) suspend() method. 132. What method must be implemented by all threads?  ...

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HCL & HP Java/J2EE Technical question Set 1.12

121. When a thread blocks on I/O, what state does it enter?             A thread enters the waiting state when it blocks on I/O. 122. When a thread is created and started, what is its initial state?             A thread is in the ready state after it has been created and started. 123. What invokes a thread’s run() method?             After a thread is...

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HCL & HP Java/J2EE Technical question Set 1.11

111. What is the GregorianCalendar class?             The GregorianCalendar provides support for traditional Western calendars. 112. What is the Locale class?             The Locale class is used to tailor program output to the conventions of a particular geographic, political, or cultural region. 113. What is the SimpleTimeZone class?             The...

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HCL & HP Java/J2EE Technical question Set 1.10

101. How many objects are created in the following piece of code? MyClass c1, c2, c3; c1 = new MyClass (); c3 = new MyClass (); Only 2 objects are created, c1 and c3. The reference c2 is only declared and not initialized.            102. Can a public class MyClass be defined in a source file named YourClass.java? No the source file name, if it contains a public class, must be the same as the public class name...

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HCL & HP Java/J2EE Technical question Set 1.9

91. Can a .java file contain more than one java classes? Yes, a .java file contain more than one java classes, provided at the most one of them is a public class. 92. Is String a primitive data type in Java? No String is not a primitive data type in Java, even though it is one of the most extensively used object. Strings in Java are instances of String class defined in java.lang package. 93. Is main a keyword in Java? No, main is not a...

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