Why do we get NullPointerException in Java?

What Causes NullPointerException. The NullPointerException occurs due to a situation in application code where an uninitialized object is attempted to be accessed or modified. Essentially, this means the object reference does not point anywhere and has a null value.

Can we throw NullPointerException?

Null is the default value of the object type, you can also manually assign null to objects in a method. But, you cannot use an object with null value or (a null value instead of an object) if you do so, a NullPointerException will be thrown.

Is SQLException checked or unchecked?

The classes that directly inherit the Throwable class except RuntimeException and Error are known as checked exceptions. For example, IOException, SQLException, etc. Checked exceptions are checked at compile-time.

What is a ClassCastException in Java?

ClassCastException is a runtime exception raised in Java when we try to improperly cast a class from one type to another. It’s thrown to indicate that the code has attempted to cast an object to a related class, but of which it is not an instance.

How does Java handle checked and unchecked exceptions?

Difference Between Checked and Unchecked Exceptions in Java

1. A checked exception is caught at compile time whereas a runtime or unchecked exception is, as it states, at runtime.
2. A checked exception must be handled either by re-throwing or with a try catch block, whereas an unchecked isn’t required to be handled.

How do you handle exceptions in Java?

The try-catch is the simplest method of handling exceptions. Put the code you want to run in the try block, and any Java exceptions that the code throws are caught by one or more catch blocks. This method will catch any type of Java exceptions that get thrown. This is the simplest mechanism for handling exceptions.

Why FileNotFoundException is checked exception?

FileNotFoundException is a checked exception in Java. Anytime, we want to read a file from the filesystem, Java forces us to handle an error situation where the file may not be present in the place. In the above example, you will get compile-time error with the message – Unhandled exception type FileNotFoundException .

Can we catch runtime exception?

RuntimeException is intended to be used for programmer errors. As such it should never be caught. There are a few cases where it should be: you are calling code that comes from a 3rd party where you do not have control over when they throw exception.