# list2params proc

Source: https://ref.dm-lang.org/proc/list2params

### Format
> `list2params(List)`

### Args
> List: List to encode as a text string.

This instruction converts a list of parameter names and associated values into a single text string suitable for use in a URL or similar situation. The format of the resulting text string is:

```dm /list2params/
"name1=value1&name2=value2&..."
```

Special characters such as '=' and '&' inside the parameter names or values are written in the form: `%xx` where `xx` are two hexadecimal digits representing the ASCII value of the character. For [Unicode](https://ref.dm-lang.org/notes/Unicode.md) characters, their UTF-8 encoding will be processed this way, which may make up multiple `%xx` sequences. In addition, spaces are converted to `+`.

This parameter format is the same one used by most HTML forms and is known by the MIME type `application/x-www-form-urlencoded`. It is often used in DM to pack information into topic links.

The original list has items `"name1"`, `"name2"`, and so on. These in turn are associated with the corresponding values `"value1"`, `"value2"`, and so on.

```dm /list2params/
var/plist[0]

plist["offense"] = "jwalk"
plist["time"] = "10:00"

usr << list2params(plist)
```

The above example creates a simple parameter list which associates the item "offense" with the value "jwalk" and the item "time" with the value "10:00". This will produce the text string "offense=jwalk&time=10:00".

Object values in the list (like say a mob) get turned into references in the parameter text, just as though you had embedded them with "\\ref[Object]". When read back in with params2list(), you could convert these values back into real references by using locate().

### See also
- [Topic proc (client)](https://ref.dm-lang.org/client/proc/Topic.md)
- [list associations](https://ref.dm-lang.org/list/associations.md)
- [params var (world)](https://ref.dm-lang.org/world/var/params.md)
- [params2list proc](https://ref.dm-lang.org/proc/params2list.md)
- [text2num proc](https://ref.dm-lang.org/proc/text2num.md)