[#boost-urls-url_base-params]
= xref:boost.adoc[boost]::xref:boost/urls.adoc[urls]::xref:boost/urls/url_base.adoc[url_base]::params
:relfileprefix: ../../../
:mrdocs:


Return the query as a container of parameters

== Synopsis


Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/url_base.hpp#L2110[boost/url/url_base.hpp]>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
xref:boost/urls/params_ref.adoc[params_ref]
xref:boost/urls/url_base/params-03.adoc[params]() noexcept;
----

[.small]#xref:boost/urls/url_base/params-03.adoc[_» more..._]#

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
xref:boost/urls/params_view.adoc[params_view]
xref:boost/urls/url_base/params-0b.adoc[params]() const noexcept;
----

[.small]#xref:boost/urls/url_base/params-0b.adoc[_» more..._]#

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
xref:boost/urls/params_ref.adoc[params_ref]
xref:boost/urls/url_base/params-0c.adoc[params](xref:boost/urls/encoding_opts.adoc[encoding_opts] opt) noexcept;
----

[.small]#xref:boost/urls/url_base/params-0c.adoc[_» more..._]#

== Description


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


=== Example

[,cpp]
----
params_ref pv = url( "/sql?id=42&name=jane%2Ddoe&page+size=20" ).params();
----

=== Complexity

Constant.


=== Exception Safety

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)]



== Parameters


|===
| Name | Description

| *opt*
| The options for decoding. If        this parameter is omitted, the `space_as_plus`        is used.


|===

== See Also


xref:boost/urls/url_base/encoded_params-06.adoc[encoded_params],            xref:boost/urls/url_base/remove_query.adoc[remove_query],            xref:boost/urls/url_base/set_encoded_query.adoc[set_encoded_query],            xref:boost/urls/url_base/set_query.adoc[set_query].






[.small]#Created with https://www.mrdocs.com[MrDocs]#