Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# IS\_CHAR function
<a name="r_is_char"></a>

Checks whether a value is a `CHAR`. The IS\_CHAR function returns `true` for strings that have only ASCII characters, because the CHAR type can store only characters that are in the ASCII format. The function returns `false` for any other values.

## Syntax
<a name="r_is_char-synopsis"></a>

```
IS_CHAR(super_expression)
```

## Arguments
<a name="r_is_char-arguments"></a>

*super\_expression*  
A `SUPER` expression or column.

## Return type
<a name="r_is_char-returns"></a>

`BOOLEAN`

## Examples
<a name="r_is_char_example"></a>

To check if `t` is a `CHAR` using the IS\_CHAR function, use the following example.

```
CREATE TABLE t(s SUPER);

INSERT INTO t VALUES ('t');

SELECT s, IS_CHAR(s) FROM t;

+-----+---------+
|  s  | is_char |
+-----+---------+
| "t" | true    |
+-----+---------+
```