Files
json/docs
Niels Lohmann 13d2b3e224 Return the first member of duplicate keys from lookups again
Looking up the last member of a duplicate key cannot stop at a match, so
every lookup scanned the whole object (1.6 to 3.4 times slower for small
objects). operator[](key), at, find, value, contains, count, and JSON
pointer resolution return the first member again, as yyjson and simdjson
do; materialize() and get<map>() keep the last value, as parse().

The documentation says so in the feature page and on each lookup page,
and explains how to get the value parse() would give. The integer index
templates and the discarded chaining of operator[] stay.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-09 23:20:51 +02:00
..
2025-04-11 10:41:14 +02:00
2025-04-11 10:41:14 +02:00

Documentation

Generate documentation

Note on documentation: The source files contain links to the online documentation at https://json.nlohmann.me.
This URL provides the most recent documentation and also applies to previous versions. Documentation for deprecated functions is not removed; instead, it is marked as deprecated.

If you want to view the documentation for a specific tag or commit hash, you can generate it locally as follows (example using tag v3.10.2):

git clone https://github.com/nlohmann/json.git
cd json
git checkout v3.10.2
make install_venv serve -C docs/mkdocs

Open http://127.0.0.1:8000/ in your browser. Replace any URL in the source code that points to https://json.nlohmann.me with http://127.0.0.1:8000 to view the documentation for the selected tag or commit hash.