# Function setSize Count the number of elements of a (multi)set. When a second parameter is 'true', count only the unique values. A multi-dimension array will be converted to a single-dimension array before the operation. ## Syntax ```js math.setSize(set) math.setSize(set, unique) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `a` | Array | Matrix | A multiset ### Returns Type | Description ---- | ----------- number | The number of elements of the (multi)set ### Throws Type | Description ---- | ----------- ## Examples ```js math.setSize([1, 2, 2, 4]) // returns 4 math.setSize([1, 2, 2, 4], true) // returns 3 ``` ## See also [setUnion](setUnion.md), [setIntersect](setIntersect.md), [setDifference](setDifference.md)