json/docs/examples/value__json_ptr.cpp
Florian Albrechtskirchinger 9aafcbe965
Move UDLs out of the global namespace (#3605)
* Move UDLs into nlohmann::literals::json_literals namespace

* Add 'using namespace' to unit tests

* Add 'using namespace' to examples

* Add 'using namespace' to README

* Move UDL mkdocs pages out of basic_json/

* Update documentation

* Update docset index

* Add JSON_GlobalUDLs CMake option

* Add unit test

* Build examples without global UDLs

* Add CI target
2022-07-31 17:38:52 +02:00

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#include <iostream>
#include <nlohmann/json.hpp>
using json = nlohmann::json;
using namespace nlohmann::literals;
int main()
{
// create a JSON object with different entry types
json j =
{
{"integer", 1},
{"floating", 42.23},
{"string", "hello world"},
{"boolean", true},
{"object", {{"key1", 1}, {"key2", 2}}},
{"array", {1, 2, 3}}
};
// access existing values
int v_integer = j.value("/integer"_json_pointer, 0);
double v_floating = j.value("/floating"_json_pointer, 47.11);
// access nonexisting values and rely on default value
std::string v_string = j.value("/nonexisting"_json_pointer, "oops");
bool v_boolean = j.value("/nonexisting"_json_pointer, false);
// output values
std::cout << std::boolalpha << v_integer << " " << v_floating
<< " " << v_string << " " << v_boolean << "\n";
}