> ## 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.

# Conversion Functions

## `format`

Returns a formatted string using the specified format string and arguments.

*Supported Signatures*

```sql theme={null}
function format(varchar, $1) returns varchar
function format(varchar, $1, $2) returns varchar
function format(varchar, $1, $2, $3) returns varchar
function format(varchar, $1, $2, $3, $4) returns varchar
function format(varchar, $1, $2, $3, $4, $5) returns varchar
```

[🔗 Official Documentation](https://trino.io/docs/current/functions/conversion.html#format)

## `format_number`

Returns a formatted string using a unit symbol.

*Supported Signatures*

```sql theme={null}
function format_number(bigint) returns varchar
function format_number(double) returns varchar
```

[🔗 Official Documentation](https://trino.io/docs/current/functions/conversion.html#format_number)

## `parse_data_size`

Parses string of format value unit into a number, where value is the fractional number of unit values.

*Supported Signatures*

```sql theme={null}
function parse_data_size(varchar) returns decimal(38, 0)
```

[🔗 Official Documentation](https://trino.io/docs/current/functions/conversion.html#parse_data_size)

## `parse_presto_data_size`

Parses string of format value unit into a number, where value is the fractional number of unit values.

*Supported Signatures*

```sql theme={null}
function parse_presto_data_size(varchar) returns decimal(38, 0)
```

[🔗 Official Documentation](https://trino.io/docs/current/functions/conversion.html#parse_data_size)

## `typeof`

Returns the name of the type of the provided expression.

*Supported Signatures*

```sql theme={null}
function typeof($1) returns varchar
```

[🔗 Official Documentation](https://trino.io/docs/current/functions/conversion.html#typeof)