mirror of
https://github.com/nlohmann/json.git
synced 2024-08-21 12:32:27 +02:00
81 lines
1.9 KiB
C++
81 lines
1.9 KiB
C++
#include <iostream>
|
|
#include <nlohmann/json.hpp>
|
|
|
|
using json = nlohmann::json;
|
|
using namespace nlohmann::literals;
|
|
|
|
int main()
|
|
{
|
|
// create a JSON value
|
|
const json j =
|
|
{
|
|
{"number", 1}, {"string", "foo"}, {"array", {1, 2}}
|
|
};
|
|
|
|
// read-only access
|
|
|
|
// output element with JSON pointer "/number"
|
|
std::cout << j.at("/number"_json_pointer) << '\n';
|
|
// output element with JSON pointer "/string"
|
|
std::cout << j.at("/string"_json_pointer) << '\n';
|
|
// output element with JSON pointer "/array"
|
|
std::cout << j.at("/array"_json_pointer) << '\n';
|
|
// output element with JSON pointer "/array/1"
|
|
std::cout << j.at("/array/1"_json_pointer) << '\n';
|
|
|
|
// out_of_range.109
|
|
try
|
|
{
|
|
// try to use an array index that is not a number
|
|
json::const_reference ref = j.at("/array/one"_json_pointer);
|
|
}
|
|
catch (const json::parse_error& e)
|
|
{
|
|
std::cout << e.what() << '\n';
|
|
}
|
|
|
|
// out_of_range.401
|
|
try
|
|
{
|
|
// try to use an invalid array index
|
|
json::const_reference ref = j.at("/array/4"_json_pointer);
|
|
}
|
|
catch (const json::out_of_range& e)
|
|
{
|
|
std::cout << e.what() << '\n';
|
|
}
|
|
|
|
// out_of_range.402
|
|
try
|
|
{
|
|
// try to use the array index '-'
|
|
json::const_reference ref = j.at("/array/-"_json_pointer);
|
|
}
|
|
catch (const json::out_of_range& e)
|
|
{
|
|
std::cout << e.what() << '\n';
|
|
}
|
|
|
|
// out_of_range.403
|
|
try
|
|
{
|
|
// try to use a JSON pointer to a nonexistent object key
|
|
json::const_reference ref = j.at("/foo"_json_pointer);
|
|
}
|
|
catch (const json::out_of_range& e)
|
|
{
|
|
std::cout << e.what() << '\n';
|
|
}
|
|
|
|
// out_of_range.404
|
|
try
|
|
{
|
|
// try to use a JSON pointer that cannot be resolved
|
|
json::const_reference ref = j.at("/number/foo"_json_pointer);
|
|
}
|
|
catch (const json::out_of_range& e)
|
|
{
|
|
std::cout << e.what() << '\n';
|
|
}
|
|
}
|