What are exception types in Java?

What are exception types in Java?

I'm glad you asked!

Exception types in Java refer to the specific categories of exceptions that can occur during the execution of a program. In other words, these are the possible errors or unexpected situations that can arise when a program is running, and how Java handles them.

In Java, there are two main categories of exceptions: checked exceptions and unchecked exceptions.

Checked Exceptions: These are the ones that must be explicitly handled by the programmer using try-catch blocks. If a checked exception occurs at runtime, the program will terminate abruptly, and no further execution is possible until the exception is properly handled. Examples of checked exceptions include:

Unchecked Exceptions: These are the ones that don't require explicit handling using try-catch blocks. They can occur at runtime, but the program will not terminate abruptly unless they're explicitly handled or propagated to a higher level. Examples of unchecked exceptions include:

Other notable exception types in Java include:

In summary, Java's exception handling mechanism provides a robust way to manage errors and unexpected situations by categorizing them into checked and unchecked exceptions. By understanding these categories and their characteristics, developers can effectively handle and respond to the various types of exceptions that may arise in their programs.

What is runtime and compile time exception in Java?

I'm happy to help you with that!

In Java, runtime exceptions and compile-time exceptions are two distinct categories of errors that can occur when executing a program.

Runtime Exceptions:

A runtime exception is an error that occurs while the program is running or during execution. It is typically detected by the Java Virtual Machine (JVM) at runtime and can be thrown by any piece of code, including methods in libraries or frameworks. Runtime exceptions are not checked by the compiler before the code runs.

Examples of runtime exceptions include:

When a runtime exception occurs, the JVM will terminate the program or throw another exception (like RuntimeException), depending on how well your code is designed to handle errors.

Compile-Time Exceptions:

A compile-time exception, also known as a checked exception, is an error that the compiler checks for before the code runs. The Java compiler checks if the code potentially throws certain types of exceptions and requires you to explicitly catch or declare them using the throws keyword in method declarations.

Examples of compile-time exceptions include:

When you try to compile code that potentially throws a checked exception but doesn't handle it correctly, the compiler will throw an error message demanding you to add proper exception handling using try-catch blocks or declare the exception in method declarations.

To illustrate this concept:

// Compile-time exception: IOException (throws statement required)
public void readData() throws IOException {
// code that might throw an IOException
}
// Runtime exception: NullPointerException (not checked by compiler)
public void accessObject() {
Object obj = null;
System.out.println(obj.toString());  // runtime exception!
}

In conclusion, runtime exceptions occur during program execution and are not checked by the compiler. Compile-time exceptions, on the other hand, are checked by the compiler before code runs, requiring explicit handling or declaration of potential exceptions.

I hope this helps clarify the difference between these two types of Java exceptions!