[#BloombergLP-bdljsn-Json-contains] = xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdljsn.adoc[bdljsn]::xref:BloombergLP/bdljsn/Json.adoc[Json]::contains :relfileprefix: ../../../ :mrdocs: Return `true` if the `JsonObject` held by this `Json` object contains a member whose key is equivalent to the specified `key`, and return `false` otherwise. The behavior is undefined unless `true == isObject()`. == Synopsis Declared in `<bdljsn_json.h>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- bool contains(std::string_view const& key) const; ---- [.small]#Created with https://www.mrdocs.com[MrDocs]#