> For the complete documentation index, see [llms.txt](https://200ok.gitbook.io/200ok-documents/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://200ok.gitbook.io/200ok-documents/user-manual/built-in-functions/logical/nullvalue.md).

# nullValue

nullValue() function is the Standard function available in 200OK.

**Description** : The nullValue function checks if an expression is null and returns a substitute expression if it is. If the expression is not null, it returns the original expression value.

**Syntax** : fx\_nullValue(expression, substitute\_expression)

**Example** : fx\_nullValue(null, 11>10) returns 11>10 as the response because the original expression was null.

Here we go with simple scenario using the above function.

**Request Side** : 

<figure><img src="https://lh7-us.googleusercontent.com/aMb7V2NKOPO_DUMpvs6kaag4uYX1L88euwXNhbavgPRMvdNHfy0Zc6UzS5_JC7S6phhme4SZT5C53K4Zq7zHW6Nf-iqqjkAz3buNmTKRME7teSK8eo33tT1Mxuj6eDxbbRBEJZwy5uTpTYBquanHgsg" alt=""><figcaption></figcaption></figure>

**Response Side** :&#x20;

<figure><img src="https://lh7-us.googleusercontent.com/sAuhjMGG06jHQIQ_OWVPFyEhDOiVb_jlPzv1b5xL8YjzGsTUDXkQEDfmHMB-Wrj0G12VUfyb399tLgtm5DaP-roOW5PLmk6zYCaxlYs7T6LkuGVqDl-7Iq1_WSgYYnZhDAAN5tdej_gs_E_A8hyvN30" alt=""><figcaption></figcaption></figure>

<figure><img src="https://lh7-us.googleusercontent.com/sXdI8LhF9Gqfz1crcESMg6NdsaEuW-GWbz4jVFtquZ-NQOgVsC_d0HksTR56_i5IHZ6ckp0rPq2ZYZOcQJhwta_G4n_fHki8xpIw5PDe3MEhBfqS9jID2R2M76LPjUdZ3xaE5iYzh3aNekN9jD_nHEw" alt=""><figcaption></figcaption></figure>