# LENGTH

> LENGTH function in StackQL: the number of characters in a string, or the number of bytes in a BLOB.

Source: https://stackql.io/language-spec/functions/string/length

Returns the number of characters in a string input expression prior to the first `NULL` character, or the number of bytes in a BLOB expression.  

See also:  
[[` SELECT `]](/language-spec/select) 

* * * 

:::info

To get the length of a JSON array use the [**JSON_ARRAY_LENGTH**](/language-spec/functions/json/json_array_length) function.

:::

## Syntax

```sql
SELECT LENGTH(expression) FROM <multipartIdentifier>;
```

## Arguments

__*expression*__  
An ASCII string or a BLOB.

> Returns `NULL` if *expression* is `NULL`.

> If *expression* is numeric then the length of a string representation of *expression* is returned.

## Return Value(s)
Returns an integer.

* * *

## Examples

### Return the length of a string column

```sql
SELECT name, length(name) AS len
FROM google.compute.instances 
WHERE project = 'stackql-demo' 
AND zone = 'australia-southeast1-a';
```

For more information, see [https://www.sqlite.org/lang_corefunc.html#length](https://www.sqlite.org/lang_corefunc.html#length)