# Function isNegative Test whether a value is negative: smaller than zero. The function supports types `number`, `BigNumber`, `Fraction`, and `Unit`. The function is evaluated element-wise in case of Array or Matrix input. ## Syntax ```js math.isNegative(x) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `x` | number | BigNumber | Fraction | Unit | Array | Matrix | Value to be tested ### Returns Type | Description ---- | ----------- boolean | Returns true when `x` is larger than zero. Throws an error in case of an unknown data type. ## Examples ```js math.isNegative(3) // returns false math.isNegative(-2) // returns true math.isNegative(0) // returns false math.isNegative(-0) // returns false math.isNegative(math.bignumber(2)) // returns false math.isNegative(math.fraction(-2, 5)) // returns true math.isNegative('-2') // returns true math.isNegative([2, 0, -3]') // returns [false, false, true] ``` ## See also [isNumeric](isNumeric.md), [isPositive](isPositive.md), [isZero](isZero.md), [isInteger](isInteger.md)