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◆ push_back() [3/4]
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 >::push_back |
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const typename object_t::value_type & |
val | ) |
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inline |
Inserts the given element val to the JSON object. If the function is called on a JSON null value, an empty object is created before inserting val.
- Parameters
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[in] | val | the value to add to the JSON object |
- Exceptions
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type_error.308 | when called on a type other than JSON object or null; example: "cannot use push_back() with number" |
- Complexity
- Logarithmic in the size of the container, O(log(
size() )).
- Example
- The example shows how
push_back() and += can be used to add elements to a JSON object. Note how the null value was silently converted to a JSON object.
2 #include <nlohmann/json.hpp>
9 json object = {{ "one", 1}, { "two", 2}};
13 std::cout << object << '\n';
14 std::cout << null << '\n';
17 object.push_back(json::object_t::value_type( "three", 3));
18 object += json::object_t::value_type( "four", 4);
19 null += json::object_t::value_type( "A", "a");
20 null += json::object_t::value_type( "B", "b");
23 std::cout << object << '\n';
24 std::cout << null << '\n';
basic_json<> json default JSON class
Output (play with this example online): {"one":1,"two":2}
null
{"four":4,"one":1,"three":3,"two":2}
{"A":"a","B":"b"}
The example code above can be translated withg++ -std=c++11 -Isingle_include doc/examples/push_back__object_t__value.cpp -o push_back__object_t__value
- Since
- version 1.0.0
Definition at line 22945 of file json.hpp.
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