> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sdf.com/llms.txt
> Use this file to discover all available pages before exploring further.

# String Functions

## `array_concat`

*Supported Signatures*

```sql theme={null}
function array_concat(super, ...) returns super
```

[🔗 Official Documentation](https://docs.aws.amazon.com/redshift/latest/dg/r_array_concat.html)

## `get_array_length`

*Supported Signatures*

```sql theme={null}
function get_array_length(super) returns bigint
```

[🔗 Official Documentation](https://docs.aws.amazon.com/redshift/latest/dg/get_array_length.html)

## `json_array_length`

*Supported Signatures*

```sql theme={null}
function json_array_length(varchar) returns bigint
function json_array_length(varchar, boolean) returns bigint
```

[🔗 Official Documentation](https://docs.aws.amazon.com/redshift/latest/dg/JSON_ARRAY_LENGTH.html)

## `regexp_replace`

*Supported Signatures*

```sql theme={null}
function regexp_replace(varchar, varchar) returns varchar
function regexp_replace(varchar, varchar, varchar) returns varchar
function regexp_replace(varchar, varchar, varchar, bigint) returns varchar
function regexp_replace(varchar, varchar, varchar, bigint, varchar) returns varchar
```

[🔗 Official Documentation](https://docs.aws.amazon.com/redshift/latest/dg/REGEXP_REPLACE.html)

## `substr`

*Supported Signatures*

```sql theme={null}
function substr(varchar, bigint) returns varchar
function substr(varchar, bigint, bigint) returns varchar
```

[🔗 Official Documentation](https://docs.aws.amazon.com/redshift/latest/dg/c_SQL_functions.html)

## `substring`

*Supported Signatures*

```sql theme={null}
function substring(varchar, bigint) returns varchar
function substring(varchar, bigint, bigint) returns varchar
```

[🔗 Official Documentation](https://docs.aws.amazon.com/redshift/latest/dg/r_SUBSTRING.html)