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
begin
begin
boolean_t
cbegin
cend
clear
const_pointer
const_reference
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
is_array
is_boolean
is_discarded
is_null
is_number
is_number_float
is_number_integer
is_object
is_primitive
is_string
is_structured
max_size
number_float_t
number_integer_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[]
parse
parse
parse_event_t
parser_callback_t
pointer
push_back
push_back
push_back
rbegin
rbegin
reference
rend
rend
size
size_type
string_t
swap
swap
swap
swap
type
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 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.
  #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';
  }
  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