Discussion of Activity 4.4 - A program which throws an exception

Here are the expected results at each stage of this activity:

1. You should find that the program halts and reports an OutOfMemoryError exception. This type of exception is not at all common and has only come about because we have provoked it deliberately.
   
   
2. The exception should not occur this time, as most systems should be able to allocate one million ints. If it does still occur, reduce the amount of memory requested again to 1000 ints. This should work on any reasonable system. The program should complete normally and print the message:
   
   

   Successfully allocated 

3. You might think that this would have the same effect as the first experiment, after an attempt to allocate a million million ints (1000*1000*1000*1000). However, an int variable in Java cannot store a number as big as this, so the calculation "wraps around" to a negative value, and you should get messages like this:

   Try to allocate memory for -727379968 ints
   java.lang.NegativeArraySizeException 

   So the program does fail to complete, but with an exception indicating an attempt to construct an array whose size is a negative number - tricky!