bignumber

A bignumber refers to a numeric value stored and manipulated with arbitrary precision, beyond the fixed width of native binary or decimal types. Bignumbers are used when exact calculations are required or when the range of values exceeds what standard types can safely represent. They are implemented by libraries that perform arithmetic on sequences of digits rather than on built-in floating-point representations.

Arbitrary-precision arithmetic keeps every computed digit, but it trades speed for accuracy. Operations such as addition, subtraction, multiplication, division, and rounding are implemented with algorithms that handle numbers as arrays or linked lists of base digits. These libraries provide constructors, comparisons, and methods for scaling, normalization, and conversion to and from primitive types.

In programming languages, support for large numbers ranges from built-in types to external libraries. Python's int uses arbitrary precision; Java's BigInteger and BigDecimal provide integer and decimal support; JavaScript includes BigInt for integers, while libraries such as bignumber.js offer decimal arithmetics with configurable precision and rounding modes.

Common use cases include financial calculations requiring exact decimal results, large integer computations in cryptography, and simulations or scientific work where rounding errors are undesirable. Bignumbers are also employed in data processing where exact representation of large or precise values is essential.

Performance varies by implementation and configuration. More precision generally means more memory and slower operations. Typical approaches store digits in fixed-size limbs and use optimized algorithms for multiplication and division; users often choose a precision that satisfies their specific accuracy requirements.