Arbitrary Precision

This project supports arbitrary precision decimal math via the @phensley/decimal package. This package can be used on its own if desired.

Arbitrary precision means the number of digits in a number is not limited, as it is with the fixed-precision JavaScript number type.

In order to construct an arbitrary precision decimal number use the Decimal type.

The benefits of arbitrary precision arithmetic are:

• Manipulate much larger and smaller numbers without losing precision. For example 0.1 + 0.1 + 0.1 should equal exactly 0.3 not 0.30000000000000004.
• Extra control is useful when manipulating currency amounts.

There are a few tradeoffs you need to make when using arbitrary precision:

• Operations on Decimal are slower than those on number.
• To use it effectively you need to be aware of the precision or scale your particular application requires.

Example

import { Decimal, DecimalConstants } from '@phensley/cldr';

let n = new Decimal(10).divide(3, { scale: 10 });
log(n);

n = new Decimal(10).divide(6, { scale: 10 });
log(n);

const { TWO, PI } = DecimalConstants;
for (let scale = 30; scale >= 1; scale--) {
  log(TWO.multiply(PI, { scale }));
}

3.3333333333
1.6666666667
6.283185307179586476925286766559
6.28318530717958647692528676656
6.2831853071795864769252867666
6.283185307179586476925286767
6.28318530717958647692528677
6.2831853071795864769252868
6.283185307179586476925287
6.28318530717958647692529
6.2831853071795864769253
6.283185307179586476925
6.28318530717958647693
6.2831853071795864769
6.283185307179586477
6.28318530717958648
6.2831853071795865
6.283185307179586
6.28318530717959
6.2831853071796
6.283185307180
6.28318530718
6.2831853072
6.283185307
6.28318531
6.2831853
6.283185
6.28319
6.2832
6.283
6.28
6.3

See Also

• Decimal
• Rational