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, class BinaryType = std::vector<std::uint8_t>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::clear ( )

inlinenoexcept

clears the contents

Clears the content of a JSON value and resets it to the default value as if basic_json(value_t) would have been called with the current value type from type():

Value type	initial value
null	null
boolean	false
string	""
number	0
binary	An empty byte vector
object	{}
array	[]

Postcondition

Has the same effect as calling

*this = basic_json(type());

@liveexample{The example below shows the effect of clear() to different JSON types.,clear}

@complexity Linear in the size of the JSON value.

@iterators All iterators, pointers and references related to this container are invalidated.

@exceptionsafety No-throw guarantee: this function never throws exceptions.

See also

see basic_json(value_t) – constructor that creates an object with the same value than calling clear()

Since

version 1.0.0

Definition at line 23069 of file json.hpp.

    {
        switch (m_type)
        {
            case value_t::number_integer:
            {
                m_value.number_integer = 0;
                break;
            }
 
            case value_t::number_unsigned:
            {
                m_value.number_unsigned = 0;
                break;
            }
 
            case value_t::number_float:
            {
                m_value.number_float = 0.0;
                break;
            }
 
            case value_t::boolean:
            {
                m_value.boolean = false;
                break;
            }
 
            case value_t::string:
            {
                m_value.string->clear();
                break;
            }
 
            case value_t::binary:
            {
                m_value.binary->clear();
                break;
            }
 
            case value_t::array:
            {
                m_value.array->clear();
                break;
            }
 
            case value_t::object:
            {
                m_value.object->clear();
                break;
            }
 
            case value_t::null:
            case value_t::discarded:
            default:
                break;
        }
    }