:relfileprefix: ../../../
[#C8E01C04AE75744D4426AB0117A6464D2127A1C0]

= Function url_base::params

pass:v,q[Return the query as a container of parameters]


== Synopsis

Declared in header `</boost/url/url_base.hpp#L2136[boost/url/url_base.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
xref:boost/urls/params_ref.adoc[params_ref]
params(xref:boost/urls/encoding_opts.adoc[encoding_opts] opt) noexcept;
----

== Description

pass:v,q[This function returns a bidirectional] pass:v,q[view of key/value pairs over the query.]
pass:v,q[The returned view references the same]
pass:v,q[underlying character buffer; ownership]
pass:v,q[is not transferred.]
pass:v,q[Any percent-escapes in strings returned]
pass:v,q[when iterating the view are decoded first.]
pass:v,q[The container is modifiable; changes]
pass:v,q[to the container are reflected in the]
pass:v,q[underlying URL.]

=== Example
[,cpp]
----
encoding_opts opt;
opt.space_as_plus = true;
params_ref pv = url( "/sql?id=42&name=jane+doe&page+size=20" ).params(opt);
----

=== Complexity
pass:v,q[Constant.]

=== Exception Safety
pass:v,q[Throws nothing.]

=== BNF
[,cpp]
----
query           = *( pchar / "/" / "?" )

query-param     = key [ "=" value ]
query-params    = [ query-param ] *( "&" query-param )
----

=== Specification

* link:https://datatracker.ietf.org/doc/html/rfc3986#section-3.4[3.4.  Query (rfc3986)]

* link:https://en.wikipedia.org/wiki/Query_string[Query string (Wikipedia)]



== Return Value

* `params_ref` 


== Parameters

|===
| Name | Type 

| *opt*
| `encoding_opts`

|===