## `count`
The count function counts the number of times that the function is called. In a [`SELECT`](/docs/reference/query-language/statements/select.md) that aggregates with [`GROUP BY`](/docs/reference/query-language/clauses/group.md) or `GROUP ALL`, that call count is the size of each group.
_(since v3.2.5)_
When every field in the projection is a bare zero-argument `count()` (optionally aliased), SurrealDB [implies `GROUP ALL`](/docs/reference/query-language/statements/select.md#bare-count-implies-group-all). Before this change, a bare `count()` returned the constant `1` once per record.
```surql title="API DEFINITION"
count() -> 1
```
If a value is given as the first argument, then this function checks whether a given value is [truthy](/docs/reference/query-language/language-primitives/data-types/values.md#values-and-truthiness). This is useful for returning the total number of rows which match a certain condition in a [`SELECT`](/docs/reference/query-language/statements/select.md) with a `GROUP BY` or `GROUP ALL` clause.
```surql title="API DEFINITION"
count(any) -> number
```
If an array is given, this function counts the number of items in the array which are [truthy](/docs/reference/query-language/language-primitives/data-types/values.md#values-and-truthiness). If, instead, you want to count the total number of items in the given array, then use the [`array::len()`](/docs/reference/query-language/functions/database-functions/array.md#arraylen) function.
```surql title="API DEFINITION"
count(array) -> number
```
The following example shows this function, and its output, when used in a [`RETURN`](/docs/reference/query-language/statements/return.md) statement:
```surql
RETURN count();
-- 1
```
```surql
RETURN count(true);
-- 1
```
```surql
RETURN count(10 > 15);
-- 0
```
```surql
RETURN count([ 1, 2, 3, null, 0, false, (15 > 10), rand::uuid() ]);
5
```
The following examples show this function being used in a [`SELECT`](/docs/reference/query-language/statements/select.md) statement with a `GROUP ALL` clause. From 3.2.5, a projection made only of bare `count()` [implies `GROUP ALL`](/docs/reference/query-language/statements/select.md#bare-count-implies-group-all); the examples keep the explicit form.
```surql
SELECT
count()
FROM [
{ age: 33 },
{ age: 45 },
{ age: 39 }
]
GROUP ALL;
```
```surql title="Response"
[
{ count: 3 }
]
```
```surql
SELECT
count(age > 35)
FROM [
{ age: 33 },
{ age: 45 },
{ age: 39 }
]
GROUP ALL;
```
```surql title="Response"
[
{ count: 2 }
]
```
An advanced example of the count function can be seen below:
```surql
SELECT
country,
count(age > 30) AS total
FROM [
{ age: 33, country: 'GBR' },
{ age: 45, country: 'GBR' },
{ age: 39, country: 'USA' },
{ age: 29, country: 'GBR' },
{ age: 43, country: 'USA' }
]
GROUP BY country;
```
```surql title="Response"
[
{
country: 'GBR',
total: 2
},
{
country: 'USA',
total: 2
}
]
```
## Using a `COUNT` index with `count()`
_(since v3.0.0)_
A `COUNT` index can be defined to speed up `count()` when used with a `GROUP ALL` clause. This allows `count()` to access a single stored value when it is called instead of iterating over the entire table. From 3.2.5, a bare `count()` projection [implies `GROUP ALL`](/docs/reference/query-language/statements/select.md#bare-count-implies-group-all); prefer the explicit form in examples and production queries.
```surql
CREATE user;
-- One record in table, very fast
SELECT count() FROM user GROUP ALL;
-- 10,000 new records,
-- count() takes a bit longer than before
CREATE |user:10000| RETURN NONE;
SELECT count() FROM user GROUP ALL;
-- Add index, wait a moment for it to build
DEFINE INDEX user_count ON user COUNT;
-- count() very performant again
SELECT count() FROM user GROUP ALL;
```