Exceptions

[ujjawal rohra]

How could i know which exceptions are checked and which are not???

[Ankit Garg]

Exceptions which inherit from java.lang.RuntimeException or java.lang.Error class are unchecked, all other are checked...

[bhanu chowdary]

All non run-time exceptions are checked exceptions.

[ujjawal rohra]

But is there any way so that i can tell which are checked and which are unchecked only by reading their names

[Seetharaman Venkatasamy]

ujjawal rohra wrote:But is there any way so that i can tell which are checked and which are unchecked only by reading their names

Only *magician* can tell that

[Prithvi Sehgal]

I don't think so, you gotta check the official documentation for that. But for the exam, there are certain
very common exceptions which are used like NumberFormatException, NullPointerException. Many of the common ones
i guess you can remember are run-time or not.

Best Regards,

[bhanu chowdary]

ujjawal rohra wrote:But is there any way so that i can tell which are checked and which are unchecked only by reading their names

There is no such way

[Pushkar Choudhary]

Seetharaman Venkatasamy wrote:

ujjawal rohra wrote:But is there any way so that i can tell which are checked and which are unchecked only by reading their names

Only *magician* can tell that

Or the original coder

[Prithvi Sehgal]

Pushkar Choudhary wrote:

Seetharaman Venkatasamy wrote:

ujjawal rohra wrote:But is there any way so that i can tell which are checked and which are unchecked only by reading their names

Only *magician* can tell that

Or the original coder

or the JavaDocs

hth,

[Larry Chung]

ujjawal rohra wrote:How could i know which exceptions are checked and which are not???

Most programmers know the difference between checked and unchecked exceptions by:

1. a lot of years of programming experience

2. memorizing the names of a few checked and unchecked exceptions

3. "being the compiler".
For example, if you are the compiler, can you always predict that some code will throw a NullPointerException? No. Therefore, it must be a runtime (a.k.a. unchecked) exception.

[Rajeev Rnair]

ujjawal rohra wrote:How could i know which exceptions are checked and which are not???

this moslty comes with experience. For the exam purpose you need to know the common exceptions related to exam objectives and should be able to identify which are checked and which are not. For example the following are all checked exceptions. You either need to declare using "throws" or handle in a "try" "catch" block.

InterruptedException

ParseException

IOException

ClassNotFoundException

FileNotFoundException

If you don't remember these, and if these comes in an overriding question, you wont be able to answer it correctly!

the following are unchecked exceptions (or Runtime Exceptions). You don't need to handle or declare these!

NullPointerException

ArithmeticException

IllegalArgumentException

IllegalStateException

ArithmeticException

IllegalMonitorStateException

NumberFormatException

IllegalThreadStateException

good luck

[Bert Bates]

Hi Ujjawal,

Do you know why they're called 'checked' exceptions? If you get really clear on that question it can help you remember which are which.