# JSON_NULL

*LSL constant*

```lsl
string JSON_NULL = "\\u{FDD5}";
```

Return value for [llJsonValueType](/functions/llJsonValueType/) function indicating the Json data type of a given address specifier in a given string-serialized JSON text.

Also the return string value for [llJsonGetValue](/functions/llJsonGetValue/) function when the bare word 'null' is at the given address specifier in a given string-serialized JSON text.

Also used to encode the bare word 'null' within a Json text to signify an empty, valueless placeholder Value at that location (the empty LSL String, "", can be used as well for that).

## Examples

<details open>
<summary>Example 1</summary>

```lsl collapse={4-8}
// Showing usage of JSON_NULL
// within a Json text string
string jText;

default
{
    state_entry(){
        jText = llList2Json(JSON_OBJECT, ["A", 4, "B", 5]);
        llOwnerSay(jText); // jText is '{"A":4,"B":5}'
        llOwnerSay(llJsonGetValue(jText, ["B"])); // The string "5"
        jText = llJsonSetValue(jText, ["B"], JSON_NULL);
        llOwnerSay(jText); // jText is now '{"A":4,"B":null}'
        llOwnerSay(llJsonGetValue(jText, ["B"])); // The Unicode value of JSON_NULL

        }
}
```

</details>

## Known issues

From the issue templates included by the wiki article:

- BUG-3692: type=bug|&lt;s>JSON_NULL may be deceptively returned instead of JSON_INVALID when \[http://tools.ietf.org/html/rfc4627 noncompliant Json text\] is encountered by either llJsonValueType or llJsonGetValue.&lt;/s> Fixed with release 13.09.21.281328.

## See also

### Constants

| Type Flags | Value | Unicode | [Integer](/functions/llOrd/) | [URL Encoded](https://wiki.secondlife.com/wiki/Category:LSL_Encoding/URL) | HTML Encoded | Description |
| --- | --- | --- | --- | --- | --- | --- |
| [JSON_INVALID](/constants/JSON_INVALID/) |  | U+FDDO | 64976 | "%EF%B7%90" | &amp;#xFDD0; | Value returned when inputs are not well formed. |
| [JSON_OBJECT](/constants/JSON_OBJECT/) |  | U+FDD1 | 64977 | "%EF%B7%91" | &amp;#xFDD1; |  |
| [JSON_ARRAY](/constants/JSON_ARRAY/) |  | U+FDD2 | 64978 | "%EF%B7%92" | &amp;#xFDD2; |  |
| [JSON_NUMBER](/constants/JSON_NUMBER/) |  | U+FDD3 | 64979 | "%EF%B7%93" | &amp;#xFDD3; |  |
| [JSON_STRING](/constants/JSON_STRING/) |  | U+FDD4 | 64980 | "%EF%B7%94" | &amp;#xFDD4; |  |
| [JSON_NULL](/constants/JSON_NULL/) |  | U+FDD5 | 64981 | "%EF%B7%95" | &amp;#xFDD5; |  |
| [JSON_TRUE](/constants/JSON_TRUE/) |  | U+FDD6 | 64982 | "%EF%B7%96" | &amp;#xFDD6; |  |
| [JSON_FALSE](/constants/JSON_FALSE/) |  | U+FDD7 | 64983 | "%EF%B7%97" | &amp;#xFDD7; |  |
| [JSON_DELETE](/constants/JSON_DELETE/) |  | U+FDD8 | 64984 | "%EF%B7%98" | &amp;#xFDD8; | Used with [llJsonSetValue](/functions/llJsonSetValue/) to remove a key-value pair. |

### Functions

- [llJsonValueType](/functions/llJsonValueType/)
- [llJsonGetValue](/functions/llJsonGetValue/)

---

*Source: [JSON NULL](https://wiki.secondlife.com/wiki/JSON_NULL) on the Second Life Wiki. Content from the Second Life Wiki articles JSON NULL (revision 1194657, 2015-01-23), Template:LSL Constants/JSON (revision 1215249, 2023-10-29) and Template:Issues/BUG-3692 (revision 1182085, 2013-10-02), CC BY-SA 3.0.*

---

From lsl.dev: https://lsl.dev/constants/JSON_NULL/