Java exponent error at 2^31 power [duplicate]

Answer 1

An int is represented with 32 bits. Thus any value between -2^31 and 2^31-1 can be represented. Nothing out of this range.

You can use a long (64 bits), or a BigInteger (a datastructures that can represented all numbers up to the memory limit).

The disadvantage of using these structures (especially BigInteger) is that a CPU does not always offer instructions for arithmetic. Thus adding two BigInteger instances requires more time than doing this with an int or long. In case of a long, if the CPU is 32-bit, it requires at least two instructions to process this.

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On a sidenote. A CPU offers a better way to calculate the powers of two: shift operations.

You can simply write:

long value = 0x01L << power;//power of two, all in one simple instruction.

This works as follow: a shift moves bits to the left. Thus if the original value is:

  0001 1011 << 2
= 0110 1100

Shifting to the left in a binary representation is arithmetically the same as multiplying with two.

Answer 2

In general,

byte 8 bits, short 16 bits, int 32 bits, long 64 bits

For Integer(int) you can store a value in between -2^31 and 2^31 i.e., from -2,147,483,648 to 2,147,483,647

If you really want to calculate powers of 2 without any limitations (atleast as per theory), you can use strings and make multiplications accordingly.

Edit:

As Commusoft suggested, BigIntegers can also be used which improves performance over Strings.