# Function sign Compute the sign of a value. The sign of a value x is: - 1 when x > 0 - -1 when x < 0 - 0 when x == 0 For matrices, the function is evaluated element wise. ## Syntax ```js math.sign(x) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `x` | number | BigNumber | Fraction | Complex | Array | Matrix | Unit | The number for which to determine the sign ### Returns Type | Description ---- | ----------- number | BigNumber | Fraction | Complex | Array | Matrix | Unit | e The sign of `x` ## Examples ```js math.sign(3.5) // returns 1 math.sign(-4.2) // returns -1 math.sign(0) // returns 0 math.sign([3, 5, -2, 0, 2]) // returns [1, 1, -1, 0, 1] ``` ## See also [abs](abs.md)