***

id: 30c48d64-00f8-47a0-9a24-b84492b028bc
slug: /reference/unset
title: unset
description: Unset specified variables.
max-toc-depth: 3
----------------

Unset specified variables. The variables have been set either using the [`set`](/docs/swml/reference/set) command
or as a byproduct of some other statements or methods (like [`record`](/docs/swml/reference/record))

<ParamField path="unset" type="string | string[]" required={true} toc={true}>
  The name of the variable to unset (as a string) or an array of variable names to unset.
</ParamField>

## **Variable**

Any variable can be unset by this method.

## **Examples**

### Unset a single variable

<CodeBlocks>
  <CodeBlock title="YAML">
    ```yaml
    version: 1.0.0
    sections:
      main:
        - set:
            num_var: 1
        - play:
            url: 'say: The value of num_var is: ${num_var}.'
        - unset: num_var
        - play:
            url: 'say: The value of num_var is ${num_var}.'
    ```
  </CodeBlock>

  <CodeBlock title="JSON">
    ```json
    {
      "version": "1.0.0",
      "sections": {
        "main": [
          {
            "set": {
              "num_var": 1
            }
          },
          {
            "play": {
              "url": "say: The value of num_var is: ${num_var}."
            }
          },
          {
            "unset": "num_var"
          },
          {
            "play": {
              "url": "say: The value of num_var is ${num_var}."
            }
          }
        ]
      }
    }
    ```
  </CodeBlock>
</CodeBlocks>

### Unset multiple variables

<CodeBlocks>
  <CodeBlock title="YAML">
    ```yaml
    version: 1.0.0
    sections:
      main:
        - set:
            systems:
              hr:
                - tracy
                - luke
              engineering:
                john: absent
            name: john
        - play:
            url: 'say: ${systems.hr}'
        - unset:
            - systems
            - name
        # this play statement emits an error because `systems` is undefined
        # at this point so there's nothing for `play` to say.
        - play:
            url: 'say: ${systems}'
    ```
  </CodeBlock>

  <CodeBlock title="JSON">
    ```json
    {
      "version": "1.0.0",
      "sections": {
        "main": [
          {
            "set": {
              "systems": {
                "hr": [
                  "tracy",
                  "luke"
                ],
                "engineering": {
                  "john": "absent"
                }
              },
              "name": "john"
            }
          },
          {
            "play": {
              "url": "say: ${systems.hr}"
            }
          },
          {
            "unset": [
              "systems",
              "name"
            ]
          },
          {
            "play": {
              "url": "say: ${systems}"
            }
          }
        ]
      }
    }
    ```
  </CodeBlock>
</CodeBlocks>

## **See Also**

* **[Variables and Expressions](/docs/swml/reference/variables)**: Complete reference for SWML variables, scopes, and syntax
* **[set](/docs/swml/reference/set)**: Set variables in the script