What are the differences between a checked and an unchecked exception?

Exceptions are unwanted or unexpected events that occur during the execution of a program. They can disrupt the normal flow of the program, and should be handled properly to avoid crashes or unexpected behavior.

Checked exceptions are exceptions that are checked at the compile-time. These exceptions are explicitly caught or thrown in the code, and the compiler ensures their proper handling. An example of a checked exception is the FileNotFoundException, which occurs when the specified file cannot be opened.

Unchecked exceptions, on the other hand, are not checked at the compile-time. These exceptions are typically caused by programming errors, such as trying to access an out-of-bounds array element or trying to divide a number by zero. Unchecked exceptions are subclasses of the RuntimeException class. Examples include NullPointerException and ArithmeticException.

The main differences between checked and unchecked exceptions are as follows: 1. Checked exceptions are checked at compile-time, whereas unchecked exceptions are checked at runtime. 2. Checked exceptions must be explicitly caught or thrown in the code, whereas unchecked exceptions are not required to be explicitly handled. 3. Checked exceptions are usually related to recoverable situations, such as when dealing with I/O operations, and their proper handling can avoid program crashes. Unchecked exceptions, on the other hand, are often caused by programming errors and indicate bugs in the code. 4. Checked exceptions extend the java.lang.Exception class, while unchecked exceptions extend the java.lang.RuntimeException class.