json/doc/examples/back.cpp
Niels Lohmann 504012a3db
📝 cleanup after #650
As <iostream> is not included in json.hpp any more, all code examples need to include <iostream> now.
2017-07-09 11:51:38 +02:00

38 lines
1 KiB
C++

#include <iostream>
#include "json.hpp"
using json = nlohmann::json;
int main()
{
// create JSON values
json j_boolean = true;
json j_number_integer = 17;
json j_number_float = 23.42;
json j_object = {{"one", 1}, {"two", 2}};
json j_object_empty(json::value_t::object);
json j_array = {1, 2, 4, 8, 16};
json j_array_empty(json::value_t::array);
json j_string = "Hello, world";
// call back()
std::cout << j_boolean.back() << '\n';
std::cout << j_number_integer.back() << '\n';
std::cout << j_number_float.back() << '\n';
std::cout << j_object.back() << '\n';
//std::cout << j_object_empty.back() << '\n'; // undefined behavior
std::cout << j_array.back() << '\n';
//std::cout << j_array_empty.back() << '\n'; // undefined behavior
std::cout << j_string.back() << '\n';
// back() called on a null value
try
{
json j_null;
j_null.back();
}
catch (json::invalid_iterator& e)
{
std::cout << e.what() << '\n';
}
}