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

clear() 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> void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::clear ( ) inlinenoexcept Clears the content of a JSON value and resets it to the default value as if basic_json(value_t) would have been called: Value type initial value null null boolean false string "" number 0 object {} array [] Complexity Linear in the size of the JSON value. Example The example below shows the effect of clear() to different JSON types. #include <json.hpp> using json = nlohmann::json; int main() { // create JSON values json j_null; json j_boolean = true; json j_number_integer = 17; json j_number_float = 23.42; json j_object = {{"one", 1}, {"two", 2}}; json j_array = {1, 2, 4, 8, 16}; json j_string = "Hello, world"; // call clear() j_null.clear(); j_boolean.clear(); j_number_integer.clear(); j_number_float.clear(); j_object.clear(); j_array.clear(); j_string.clear(); // serialize the cleared values() std::cout << j_null << '\n'; std::cout << j_boolean << '\n'; std::cout << j_number_integer << '\n'; std::cout << j_number_float << '\n'; std::cout << j_object << '\n'; std::cout << j_array << '\n'; std::cout << j_string << '\n'; } Output (play with this example online): null false 0 0.0 {} [] "" The example code above can be translated with g++ -std=c++11 -Isrc doc/examples/clear.cpp -o clear Since version 1.0.0 Definition at line 5194 of file json.hpp.