JSON for Modern C++ 3.0

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~basic_json
| template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = int64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator>
const_iterator nlohmann::basic_json::find | ( | typename object_t::key_type | key | ) | const
| inline
  find an element in a JSON object Finds an element in a JSON object with key equivalent to key. If the element is not found or the JSON value is not an object, end() is returned. Parameters
  [in] | key | key value of the element to search for
  Returns Iterator to an element with key equivalent to key. If no such element is found, past-the-end (see end()) iterator is returned. Complexity Logarithmic in the size of the JSON object. Example The example shows how find is used. 1 #include <json.hpp> 2 3 using namespace nlohmann; 4 5 int main() 6 { 7 // create a JSON object 8 json j_object = {{"one", 1}, {"two", 2}}; 9 10 // call find 11 auto it_two = j_object.find("two"); 12 auto it_three = j_object.find("three"); 13 14 // print values 15 std::cout << std::boolalpha; 16 std::cout << "\"two\" was found: " << (it_two != j_object.end()) << '\n'; 17 std::cout << "value at key \"two\": " << *it_two << '\n'; 18 std::cout << "\"three\" was found: " << (it_three != j_object.end()) << '\n'; 19 } nlohmann::basic_json a class to store JSON values Definition: json.hpp:130 nlohmann::basic_json::end iterator end() returns an iterator to one past the last element Definition: json.hpp:3190 nlohmann::basic_json::find iterator find(typename object_t::key_type key) find an element in a JSON object Definition: json.hpp:3052 nlohmann namespace for Niels Lohmann Definition: json.hpp:55 Output (play with this example online):
      "two" was found: true
      value at key "two": 2
      "three" was found: false
  The example code above can be translated with
      g++ -std=c++11 -Isrc doc/examples/find__key_type.cpp -o find__key_type