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
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_object
is_primitive
is_string
is_structured
iterator_wrapper
iterator_wrapper
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[]
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 NumberFloatType = double, template< typename U > class AllocatorType = std::allocator>
template<typename ValueType , typename std::enable_if< not std::is_pointer< ValueType >::value , int >::type = 0>

ValueType nlohmann::basic_json::get | ( |  | ) | const

inline

Explicit type conversion between the JSON value and a compatible value.

Template Parameters

  ValueType | non-pointer type compatible to the JSON value, for instance `int` for JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for JSON arrays

Returns
  copy of the JSON value, converted to type ValueType

Exceptions

  std::domain_error | in case passed type ValueType is incompatible to JSON; example: `"type must be object, but is null"`

Complexity
  Linear in the size of the JSON value.

Example
  The example below shows several conversions from JSON values to other types. There a few things to note: (1) Floating-point numbers can be converted to integers, (2) A JSON array can be converted to a standard `std::vector<short>`, (3) A JSON object can be converted to C++ associative containers such as `std::unordered_map<std::string, json>`.
  #include <json.hpp>
  #include <unordered_map>
  using namespace nlohmann;
  int main()
  {
  // create a JSON value with different types
  json json_types =
  {
  {"boolean", true},
  {
  "number", {
  {"integer", 42},
  {"floating-point", 17.23}
  }
  },
  {"string", "Hello, world!"},
  {"array", {1, 2, 3, 4, 5}},
  {"null", nullptr}
  };
  // use explicit conversions
  auto v1 = json_types["boolean"].get<bool>();
  auto v2 = json_types["number"]["integer"].get<int>();
  auto v3 = json_types["number"]["integer"].get<short>();
  auto v4 = json_types["number"]["floating-point"].get<float>();
  auto v5 = json_types["number"]["floating-point"].get<int>();
  auto v6 = json_types["string"].get<std::string>();
  auto v7 = json_types["array"].get<std::vector<short>>();
  auto v8 = json_types.get<std::unordered_map<std::string, json>>();
  // print the conversion results
  std::cout << v1 << '\n';
  std::cout << v2 << ' ' << v3 << '\n';
  std::cout << v4 << ' ' << v5 << '\n';
  std::cout << v6 << '\n';
  for (auto i : v7)
  {
  std::cout << i << ' ';
  }
  std::cout << "\n\n";
  for (auto i : v8)
  {
  std::cout << i.first << ": " << i.second << '\n';
  }
  }
  nlohmann::basic_json
  a class to store JSON values
  Definition: json.hpp:191
  nlohmann
  namespace for Niels Lohmann
  Definition: json.hpp:88
  nlohmann::basic_json::get
  ValueType get() const
  get a value (explicit)
  Definition: json.hpp:2499
  Output (play with this example online):

      1
      42 42
      17.23 17
      Hello, world!
      1 2 3 4 5

      string: "Hello, world!"
      number: {"floating-point":17.23,"integer":42}
      null: null
      boolean: true
      array: [1,2,3,4,5]

  The example code above can be translated with

      g++ -std=c++11 -Isrc doc/examples/get__ValueType_const.cpp -o get__ValueType_const

See also
  operator ValueType() const for implicit conversion
  get() for pointer-member access

Since
  version 1.0.0

Definition at line 2499 of file json.hpp.