allocator_type array array_t at at at at at at back back basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json begin begin boolean_t cbegin cend clear const_iterator const_pointer const_reference const_reverse_iterator count crbegin crend detail::external_constructor diff difference_type dump emplace emplace_back empty end end erase erase erase erase find find flatten from_cbor from_msgpack front front get get get get get get_allocator get_ptr get_ptr get_ref get_ref insert insert insert insert insert is_array is_boolean is_discarded is_null is_number is_number_float is_number_integer is_number_unsigned is_object is_primitive is_string is_structured iterator iterator_wrapper iterator_wrapper json_serializer max_size meta number_float_t number_integer_t number_unsigned_t object object_t operator value_t operator ValueType operator!= operator!= operator!= operator+= operator+= operator+= operator+= operator< operator<< operator<< operator<= operator= operator== operator== operator== operator> operator>= operator>> operator>> operator[] operator[] operator[] operator[] operator[] operator[] operator[] operator[] operator[] operator[] parse parse parse parse parse parse parse_event_t parser_callback_t patch pointer push_back push_back push_back push_back rbegin rbegin reference rend rend reverse_iterator size size_type string_t swap swap swap swap to_cbor to_msgpack type type_name unflatten value value value value value_t value_type ~basic_json

find() [2/2] 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 = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer> const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::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. Note This method always returns end() when executed on a JSON type that is not an object. 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 or the JSON value is not an object, 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. #include <json.hpp> using json = nlohmann::json; int main() { // create a JSON object json j_object = {{"one", 1}, {"two", 2}}; // call find auto it_two = j_object.find("two"); auto it_three = j_object.find("three"); // print values std::cout << std::boolalpha; std::cout << "\"two\" was found: " << (it_two != j_object.end()) << '\n'; std::cout << "value at key \"two\": " << *it_two << '\n'; std::cout << "\"three\" was found: " << (it_three != j_object.end()) << '\n'; } 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 Since version 1.0.0 Definition at line 4606 of file json.hpp.