class Bignum < Integer

Bignum objects hold integers outside the range of Fixnum. Bignum objects are created automatically when integer calculations would otherwise overflow a Fixnum. When a calculation involving Bignum objects returns a result that will fit in a Fixnum, the result is automatically converted.

For the purposes of the bitwise operations and [], a Bignum is treated as if it were an infinite-length bitstring with 2's complement representation.

While Fixnum values are immediate, Bignum objects are not—assignment and parameter passing work with references to objects, not the objects themselves.

instance methods

Arithmetic operations

Performs various arithmetic operations on big.

big	+	aNumeric	Addition
big	-	aNumeric	Subtraction
big	*	aNumeric	Multiplication
big	/	aNumeric	Division
big	%	aNumeric	Modulo
big	**	aNumeric	Exponentiation

Bit operations

Performs various operations on the binary representations of the Bignum.

~ big			Invert bits
big	|	aNumeric	Bitwise OR
big	&	aNumeric	Bitwise AND
big	^	aNumeric	Bitwise EXCLUSIVE OR
big	<<	aNumeric	Left-shift aNumeric bits
big	>>	aNumeric	Right-shift aNumeric bits (with sign extension)

<=>

big <=> aNumeric → -1, 0, +1

Comparison—Returns -1, 0, or +1 depending on whether big is less than, equal to, or greater than aNumeric. This is the basis for the tests in Comparable.

[ ]

big[ n ] → 0, 1

Bit Reference—Returns the nth bit in the (assumed) binary representation of big, where big[0] is the least significant bit.

a = 9**15 50.downto(0) do |n| print a[n] end

produces:

000101110110100000111000011110010100111100010111001

size

big.size → anInteger

Returns the number of bytes in the machine representation of big.

(256**10 - 1).size → 12 (256**20 - 1).size → 20 (256**40 - 1).size → 40

to_f

big.to_f → aFloat

Converts big to a Float. If big doesn't fit in a Float, the result is infinity.

to_i

big.to_i → big

Returns big.

to_s

big.to_s → aString

Returns a string containing the decimal representation of big.