Wipro Java Placement Papers - Wipro Java Interview Questions and Answers updated on 19.Mar.2024

The stop(), suspend() and resume() methods have been deprecated in JDK 1.2.

The range of the char type is 0 to 2^16 - 1.

The setLayout() method is used to specify a container's layout.

A task's priority is an integer value that identifies the relative order in which it should be executed with respect to other tasks. The scheduler attempts to schedule higher priority tasks before lower priority tasks.

A thread enters the waiting state when it blocks on I/O.

Unicode requires 16 bits and ASCII require 7 bits. Although the ASCII character set uses only 7 bits, it is usually represented as 8 bits. UTF-8 represents characters using 8, 16, and 18 bit patterns. UTF-16 uses 16-bit and larger bit patterns.

Yes, a lock can be acquired on a class. This lock is acquired on the class's Class object.

If a checked exception may be thrown within the body of a method, the method must either catch the exception or declare it in its throws clause.

Order of precedence determines the order in which operators are evaluated in expressions. Associatity determines whether an expression is evaluated left-to-right or right-to-left.

The EventObject class and the EventListener interface support event processing.

The Canvas, Frame, Panel, and Applet classes support painting.

The range of the short type is -(2^15) to 2^15 - 1.

An anonymous class may implement an interface or extend a superclass, but may not be declared to do both.

A thread is in the ready state after it has been created and started.

Objects that subclass the Observable class maintain a list of observers. When an Observable object is updated it invokes the update() method of each of its observers to notify the observers that it has changed state. The Observer interface is implemented by objects that observe Observable objects.

The null value is not a keyword.

The java.awt.AWTEvent class is the highest-level class in the AWT event-class hierarchy.

Most of the AWT-related events of the event-delegation model are defined in the java.awt.event package. The AWTEvent class is defined in the java.awt package.

Threads block on i/o (that is enters the waiting state) so that other threads may execute while the i/o Operation is performed.

The window, Frame and Dialog classes use a border layout as their default layout.

The digits 0 through 9 may not be used as the first character of an identifier but they may be used after the first character of an identifier.

It uses those low order bytes of the result that can fit into the size of the type allowed by the operation.

The sizeof operator is not a keyword.

The Collections API is a set of classes and interfaces that support operations on collections of objects.

Garbage collection does not guarantee that a program will not run out of memory. It is possible for programs to use up memory resources faster than they are garbage collected. It is also possible for programs to create objects that are not subject to garbage collection.

The >> operator carries the sign bit when shifting right. The >>> zero-fills bits that have been shifted out.

With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object's value. This often leads to significant errors.

Wrapped classes are classes that allow primitive types to be accessed as objects.

A transient variable is a variable that may not be serialized.

Yes, a for statement can loop indefinitely. For example, consider the following:

for(;Wink ;

A (non-local) inner class may be declared as public, protected, private, static, final, or abstract.

An object's finalize() method cannot be invoked by the garbage collector while the object is still reachable. However, an object's finalize() method may be invoked by other objects.

Under preemptive scheduling, the highest priority task executes until it enters the waiting or dead states or a higher priority task comes into existence. Under time slicing, a task executes for a predefined slice of time and then reenters the pool of ready tasks. The scheduler then determines which task should execute next, based on priority and other factors.

The Iterator interface is used to step through the elements of a Collection.

Clipping is the process of confining paint operations to a limited area or shape.

A native method is a method that is implemented in a language other than Java.

 

The List interface provides support for ordered collections of objects.

The Panel and Applet classes use the FlowLayout as their default layout.

The readLine() method returns null when it has reached the end of a file.

When a thread terminates its processing, it enters the dead state.

The Vector class provides the capability to implement a growable array of objects.

The preferred size of a component is the minimum component size that will allow the component to display normally.

A package statement must appear as the first line in a source code file (excluding blank lines and comments).

The CheckboxMenuItem class extends the MenuItem class to support a menu item that may be checked or unchecked.

When a task invokes its yield() method, it returns to the ready state. When a task invokes its sleep() method, it returns to the waiting state.