We can create a exception sub class by extending Exception class available in java
Here is a code snippet illustrating exception handling: try { int a= 3 / 0 ; } catch ( ArithmeticException e ) { System.out.println ("An ArithmeticException has occured"); } finally { // some code }
A class can be a subclass of another class, not of itself.A class can be a subclass of another class, not of itself.A class can be a subclass of another class, not of itself.A class can be a subclass of another class, not of itself.
with new operator
Yes a user defined exception can have any number of methods in it. A user defined exception is nothing but a Java class created for a specific purpose. Just like ordinary Java classes, you can have any number of methods in it...
A checked exception is an exception which the Java source code must deal with, either by catching it or declaring it to be thrown. Unchecked exceptions are all exceptions which do not follow this rule. When an unchecked exception is thrown, it is usually caused by a misuse of code - passing a null or otherwise incorrect argument. This includes classes like NullPointerException and IllegalArgumentException. Checked exceptions are generally caused by faults outside of the code itself - missing resources, networking errors, and problems with threads come to mind. These could include subclasses of FileNotFoundException, UnknownHostException, etc. The Java documentation (link below) gives some loose guidelines to follow when trying to decide which type of exception to use: "If a client can reasonably be expected to recover from an exception, make it a checked exception. If a client cannot do anything to recover from the exception, make it an unchecked exception." From a purely code-oriented point of view, a checked exception is a subclass of Exception, while an unchecked exception is a subclass of RuntimeException.
To handle the exceptions in large programs
No.
Here is a code snippet illustrating exception handling: try { int a= 3 / 0 ; } catch ( ArithmeticException e ) { System.out.println ("An ArithmeticException has occured"); } finally { // some code }
One might use the Java subclass "SimpleDateFormat" when programming a Java application that needs to display the date. This would be then be used to show the user the current date in real time.
A class can be a subclass of another class, not of itself.A class can be a subclass of another class, not of itself.A class can be a subclass of another class, not of itself.A class can be a subclass of another class, not of itself.
with new operator
Yes a user defined exception can have any number of methods in it. A user defined exception is nothing but a Java class created for a specific purpose. Just like ordinary Java classes, you can have any number of methods in it...
Subtype polymorphism in Java allows objects of a subclass to be treated as objects of their superclass. This means that a subclass can be used wherever its superclass is expected, allowing for more flexibility and reusability in code. This is achieved through inheritance and method overriding, where a subclass can provide its own implementation of methods defined in its superclass.
java exception
A checked exception is an exception which the Java source code must deal with, either by catching it or declaring it to be thrown. Unchecked exceptions are all exceptions which do not follow this rule. When an unchecked exception is thrown, it is usually caused by a misuse of code - passing a null or otherwise incorrect argument. This includes classes like NullPointerException and IllegalArgumentException. Checked exceptions are generally caused by faults outside of the code itself - missing resources, networking errors, and problems with threads come to mind. These could include subclasses of FileNotFoundException, UnknownHostException, etc. The Java documentation (link below) gives some loose guidelines to follow when trying to decide which type of exception to use: "If a client can reasonably be expected to recover from an exception, make it a checked exception. If a client cannot do anything to recover from the exception, make it an unchecked exception." From a purely code-oriented point of view, a checked exception is a subclass of Exception, while an unchecked exception is a subclass of RuntimeException.
Subclasses are classes that inherit from parent classes. i.e. ArrayList is a subclass of List.
Java does not have multiple inheritance, so no. Java can use multiple interfaces, though, with the "implements" keyword.
exception
class MyClass extends AnotherClass {}
Java does not support multiple inheritance; a subclass cannot have more than one parent. Java compensates for this with interfaces. A class can implement multiple interfaces, but can only extend one class.
Easy: there is no exception-handling in C.
False. A method with the same signature in both the superclass and its subclass is known as method overriding, and is a valid concept in Java.
Exception handling should be used in Java in all cases where you as a programmer suspect that your code might throw some exceptions or create errors that might look ugly when a user is using the application. In such cases you use exception handling to catch and handle the exception and exit gracefully. You use the try - catch block in Java for exception handling.
A JButton on Java is a button used for G.U.I (graphical user interface) and displays a button on a window created which can be programmed for different tasks.
we do it using the throw keyword.