What does BigInteger having no limit mean?

java biginteger integer-overflow
Geek picture Geek · Aug 23, 2012 · Viewed 67.3k times · Source

I looked into this stackoverflow question relating to Big Integer and specifically I do not understand this line (the words in italics):

In the BigInteger class, I have no limits and there are some helpful functions there but it is pretty depressing to convert your beautiful code to work with the BigInteger class, specially when primitive operators don't work there and you must use functions from this class.

I don't know what I am missing but to represent something that has no limit you would require infinite memory ? Whats is the trick here ?

Answer

Graham Borland picture Graham Borland · Aug 23, 2012

There is no theoretical limit. The BigInteger class allocates as much memory as it needs for all the bits of data it is asked to hold.

There are, however, some practical limits, dictated by the memory available. And there are further technical limits, although you're very unlikely to be affected: some methods assume that the bits are addressable by int indexes, so things will start to break when you go above Integer.MAX_VALUE bits.

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