Java what type of object

Improve this answer. This is so painful. Currently we have to implement Pattern Matching ourselves in every project. Proposal to add to language. However, in this case all the classes listed are final , so they have no subclasses.

Thus instanceof is probably fine here. Nick S. I'll remove my comments as they are irrelevant. You want instanceof : if value instanceof Integer This will be true even for subclasses, which is usually what you want, and it is also null-safe.

If you really need the exact same class, you could do if value. Thilo Thilo k 94 94 gold badges silver badges bronze badges. Use value instanceof YourClass. Konstantin V. Salikhov Konstantin V. In this example, we have the objects var1 and var2 that are checked with these three types: Integer , String , and Double ; if any of the conditions meet, we can execute a different code. Because var1 is of type Integer , the condition var1 instanceOf Integer will become true, and var2 is Double so, var2 instanceOf Double will become true.

We checked the types of wrapper classes, but in this example, we get the type of three objects of three manually-created classes. Now we want to know the type of objects of all these classes. In other words, this method behaves exactly as if it simply performs the call wait 0. The thread releases ownership of this monitor and waits until another thread notifies threads waiting on this object's monitor to wake up either through a call to the notify method or the notifyAll method.

Throws: IllegalMonitorStateException - if the current thread is not the owner of the object's monitor. See Also: notify , notifyAll finalize protected void finalize throws Throwable Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

A subclass overrides the finalize method to dispose of system resources or to perform other cleanup. The general contract of finalize is that it is invoked if and when the Java TM virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized.

The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize , however, is to perform cleanup actions before the object is irrevocably discarded. The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition. The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked.

If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates. After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.

The finalize method is never invoked more than once by a Java virtual machine for any given object. Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.

Object public class Object Class Object is the root of the class hierarchy. Every class has Object as a superclass. All objects, including arrays, implement the methods of this class. Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. Causes the current thread to wait until another thread invokes the notify method or the notifyAll method for this object.

Causes the current thread to wait until either another thread invokes the notify method or the notifyAll method for this object, or a specified amount of time has elapsed. Causes the current thread to wait until another thread invokes the notify method or the notifyAll method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.

The returned Class object is the object that is locked by static synchronized methods of the represented class. Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

Indicates whether some other object is "equal to" this one. In simple words, it is a way of categorizing the classes and interfaces. When developing applications in Java, hundreds of classes and interfaces will be written, therefore categorizing these classes is a must as well as makes life much easier. In Java if a fully qualified name, which includes the package and the class name is given, then the compiler can easily locate the source code or classes.

Import statement is a way of giving the proper location for the compiler to find that particular class. First open notepad and add the following code. Remember this is the Employee class and the class is a public class. Now, save this source file with the name Employee. The Employee class has four instance variables - name, age, designation and salary.

The class has one explicitly defined constructor, which takes a parameter. As mentioned previously in this tutorial, processing starts from the main method. Therefore, in order for us to run this Employee class there should be a main method and objects should be created. We will be creating a separate class for these tasks. Following is the EmployeeTest class, which creates two instances of the class Employee and invokes the methods for each object to assign values for each variable.

In the next session, we will discuss the basic data types in Java and how they can be used when developing Java applications. Java - Object and Classes Advertisements.