allocator_type array array_t at at at at back back basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json 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_pointer const_reference const_reverse_iterator count crbegin crend difference_type dump empty end end erase erase erase erase find find front front 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_wrapper iterator_wrapper max_size 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[] parse parse parse parse_event_t parser_callback_t pointer push_back push_back push_back rbegin rbegin reference rend rend reverse_iterator size size_type string_t swap swap swap swap type value value value_t value_type ~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 NumberUnsignedType = uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator> const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::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. #include <json.hpp> using namespace nlohmann; 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 3931 of file json.hpp.