bignumber.js

tip

如果考虑 bundle size 选择 big.js 否则选择 decimal.js

size: big.js < bignumber.js < decimal.js
MikeMcl/big.js
- 6.8kB/2.9kB
- minimalist arbitrary-precision library
- simplest and smallest
- 不支持 NaN, Infinity
- 不支持其他 base
- 不支持 0x
MikeMcl/bignumber.js
- MIT, JS
- 18kB/8kB
- 场景: financial
- 只要不 div 就不会丢失精度
- 存储 higher base - 计算会相对 big.js 更快
- 支持 0x
MikeMcl/decimal.js
- 31kB/12kB
- 支持 binary, octal, decimal, hexadecimal
- 支持非整数次幂 / non-integer powers, 浮点数指数
- 支持 exp, log, ln, 三角函数
- 场景: scientific, engineering, financial applications
- 最大，功能最全
参考
- big.js vs. bignumber.js vs. decimal.js
- https://npmtrends.com/big.js-vs-bignumber.js-vs-decimal.js

new BigNumber('ff.8', 16);
new Decimal('0xff.8');

// 处理小数的逻辑不一样
Bignumber.config({ DECIMAL_PLACES: 3, ROUNDING_MODE: 1 });
var x = new BigNumber('123.456789');
x.plus(1).toString(); // '124.456789'

Decimal.set({ precision: 7, rounding: 4 });
var y = new Decimal('123.456789');
y.plus(1).toString(); // '124.4568'

var	stand for	0.123	-12345.67
c	coefficient	1,2,3	1,2,3,4,5,6,7
e	exponent	-1	4
s	sign	1	-1

config	default
DECIMAL_PLACES	20
ROUNDING_MODE	4/ROUND_HALF_UP
EXPONENTIAL_AT	`[-7, 20]`
RANGE	`[-1e+9, 1e+9]`

Number

Number	-
toString(base=10)
toFixed(digits=0)	小数点后 n 位, 0 < digits < 20
toPrecision(precision?)	总的 n 个有效数字, 无 precision = toString
toExponential(fractionDigits?)	1.23e+5

Number​

Number