Checked vs Unchecked Exception in Java

In Java, there are two types of exceptions: checked exceptions and unchecked exceptions. The main difference between the two is that checked exceptions must be handled explicitly in the code, while unchecked exceptions do not.

Checked exceptions are exceptions that are checked at compile time. This means that the compiler checks to see whether the exception is handled or declared to be thrown in the method signature. If it is not handled or declared to be thrown, the code will not compile. Checked exceptions are usually related to IO operations, network connections, database access, and other operations that may fail due to external factors beyond the control of the programmer.

Unchecked exceptions, on the other hand, are not checked at compile time. This means that the compiler does not require the code to handle or declare them. Unchecked exceptions are usually related to programming errors such as null pointer dereference, division by zero, array index out of bounds, and so on.

Here are some key differences between checked and unchecked exceptions:

Checked exceptions must be handled explicitly in the code using a try-catch block or by declaring the exception to be thrown in the method signature. Unchecked exceptions can be handled, but they are not required to be

The compiler checks for the presence of a try-catch block or a throws clause for checked exceptions, but not for unchecked exceptions.

Checked exceptions must be declared in the method signature using the throws keyword, while unchecked exceptions are not required to be.

Checked exceptions can change the flow of a program, since the program must handle or declare the exception before continuing. Unchecked exceptions do not change the flow of the program unless they are unhandled and cause the program to terminate abruptly.

In general, it is good practice to handle both checked and unchecked exceptions in Java. Checked exceptions should be handled explicitly in the code, while unchecked exceptions can be handled or allowed to propagate up the call stack. Handling exceptions correctly can improve the robustness and reliability of the program, and help to prevent bugs and unexpected behavior.