ulp

Returns the size of an ulp, a unit in the last place, of this BigDecimal. An ulp of a nonzero BigDecimal value is the positive distance between this value and the BigDecimal value next larger in magnitude with the same number of digits. An ulp of a zero value is numerically equal to 1 with the _scale of this. The result is stored with the same _scale as this so the result for zero and nonzero values is equal to [1, this._scale()].