:relfileprefix: ../../../
[#boost-urls-url-set_fragment]

= xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/url.adoc[pass:[url]]::set_fragment


Set the fragment.


== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/url.hpp#L483[boost/url/url.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
xref:boost/urls/url.adoc[url]&
set_fragment(core::string_view s);
----

== Description


This function sets the fragment to the
specified string, which may be empty.
An empty fragment is distinct from
having no fragment.
Reserved characters in the string are
percent-escaped in the result.

=== Example
[,cpp]
----
assert( url("?first=john&last=doe" ).set_encoded_fragment( "john doe" ).encoded_fragment() == "john%20doe" );
----

=== Postconditions
[,cpp]
----
this->has_fragment() == true && this->fragment() == s
----

=== Complexity

Linear in `this-&gt;size() + s.size()`.

=== Exception Safety

Strong guarantee.
Calls to allocate may throw.

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

=== Specification

* link:https://datatracker.ietf.org/doc/html/rfc3986#section-3.5[3.5.  Fragment]





== Parameters

|===
| Name | Description 

| *s*
| 
The string to set.

|===




== See Also


xref:boost/urls/url_base/remove_fragment.adoc[remove_fragment]
,
xref:boost/urls/url_base/set_encoded_fragment.adoc[set_encoded_fragment]
.