:relfileprefix: ../../../
[#boost-urls-params_encoded_ref-append-07]

= xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/params_encoded_ref.adoc[pass:[params_encoded_ref]]::append


Append params


== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/params_encoded_ref.hpp#L362[boost/url/params_encoded_ref.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
xref:boost/urls/params_encoded_base/iterator.adoc[iterator]
append(xref:boost/urls/param_pct_view.adoc[param_pct_view] const& p);
----

== Description


This function appends a param to the view.



The `end()` iterator is invalidated.

=== Example
[,cpp]
----
url u;

u.encoded_params().append( { "first", "John" } );
----

=== Complexity

Linear in `this-&gt;url().encoded_query().size()`.

=== Exception Safety

Strong guarantee.
Calls to allocate may throw.
Exceptions thrown on invalid input.



== Exceptions

|===
| Name | Thrown on

| `system_error`
| 
`p` contains an invalid percent-encoding.

|===


== Return Value


An iterator to the new element.



== Parameters

|===
| Name | Description 

| *p*
| 
The param to append.

|===




