---
title: Plugin value types
description: A plugin can require that the value for a setting be a certain type, such as boolean, list, or hash. These value types are supported. This type is now...
url: https://www.elastic.co/docs/reference/logstash/plugins/value-types
products:
  - Logstash
applies_to:
  - Elastic Stack: Generally available
---

# Plugin value types
A plugin can require that the value for a setting be a certain type, such as boolean, list, or hash. These value types are supported.

## Array

This type is now mostly deprecated in favor of using a standard type like `string` with the plugin defining the `:list => true` property for better type checking. It is still needed to handle lists of hashes or mixed types where type checking is not desired.
Example:
```js
  users => [ {id => 1, name => bob}, {id => 2, name => jane} ]
```


## Lists

Not a type in and of itself, but a property types can have. This makes it possible to type check multiple values. Plugin authors can enable list checking by specifying `:list => true` when declaring an argument.
Example:
```js
  path => [ "/var/log/messages", "/var/log/*.log" ]
  uris => [ "http://elastic.co", "http://example.net" ]
```

This example configures `path`, which is a `string` to be a list that contains an element for each of the three strings. It also will configure the `uris` parameter to be a list of URIs, failing if any of the URIs provided are not valid.

## Boolean

A boolean must be either `true` or `false`. Note that the `true` and `false` keywords are not enclosed in quotes.
Example:
```js
  ssl_enable => true
```


## Bytes

A bytes field is a string field that represents a valid unit of bytes. It is a convenient way to declare specific sizes in your plugin options. Both SI (k M G T P E Z Y) and Binary (Ki Mi Gi Ti Pi Ei Zi Yi) units are supported. Binary units are in base-1024 and SI units are in base-1000. This field is case-insensitive and accepts space between the value and the unit. If no unit is specified, the integer string represents the number of bytes.
Examples:
```js
  my_bytes => "1113"  
  my_bytes => "10MiB" 
  my_bytes => "100kib"
  my_bytes => "180 mb"
```


## Codec

A codec is the name of Logstash codec used to represent the data. Codecs can be used in both inputs and outputs.
Input codecs provide a convenient way to decode your data before it enters the input. Output codecs provide a convenient way to encode your data before it leaves the output. Using an input or output codec eliminates the need for a separate filter in your Logstash pipeline.
A list of available codecs can be found at the [Codec Plugins](https://www.elastic.co/docs/reference/logstash/plugins/codec-plugins) page.
Example:
```js
  codec => "json"
```


## Hash

A hash is a collection of key value pairs specified in the format `"field1" => "value1"`. Note that multiple key value entries are separated by spaces rather than commas.
Example:
```js
match => {
  "field1" => "value1"
  "field2" => "value2"
  ...
}
# or as a single line. No commas between entries:
match => { "field1" => "value1" "field2" => "value2" }
```


## Number

Numbers must be valid numeric values (floating point or integer).
Example:
```js
  port => 33
```


## Password

A password is a string with a single value that is not logged or printed.
Example:
```js
  my_password => "password"
```


## URI

A URI can be anything from a full URL like *http://elastic.co/* to a simple identifier like *foobar*. If the URI contains a password such as *http://user:pass@example.net* the password portion of the URI will not be logged or printed.
Example:
```js
  my_uri => "http://foo:bar@example.net"
```


## Path

A path is a string that represents a valid operating system path.
Example:
```js
  my_path => "/tmp/logstash"
```


## String

A string must be a single character sequence. Note that string values are enclosed in quotes, either double or single.

## Escape sequences

By default, escape sequences are not enabled. If you wish to use escape sequences in quoted strings, you will need to set `config.support_escapes: true` in your `logstash.yml`. When `true`, quoted strings (double and single) will have this transformation:

|      |                            |
|------|----------------------------|
| Text | Result                     |
| \r   | carriage return (ASCII 13) |
| \n   | new line (ASCII 10)        |
| \t   | tab (ASCII 9)              |
| \    | backslash (ASCII 92)       |
| "    | double quote (ASCII 34)    |
| '    | single quote (ASCII 39)    |

Example:
```js
  name => "Hello world"
  name => 'It\'s a beautiful day'
```


## Field reference

A Field Reference is a special [String](#string) value representing the path to a field in an event, such as `@timestamp` or `[@timestamp]` to reference a top-level field, or `[client][ip]` to access a nested field. The *Field References Deep Dive* provides detailed information about the structure of Field References. When provided as a configuration option, Field References need to be quoted and special characters must be escaped following the same rules as [String](#string).

## Comments

Comments are the same as in perl, ruby, and python. A comment starts with a *#* character, and does not need to be at the beginning of a line. For example:
```js
# this is a comment

input {
  # ...
}
```

<note>
  Comments containing environment variable `${var}` references in `config.string` are still evaluated. Remove the `$` sign to avoid pipeline loading failures.
</note>