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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>
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
-
[in] | val | the value to add to the JSON object |
- Exceptions
-
std::domain_error | 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. 8 json object = {{ "one", 1}, { "two", 2}}; 12 std::cout << object << '\n'; 13 std::cout << null << '\n'; 16 object.push_back(json::object_t::value_type( "three", 3)); 17 object += json::object_t::value_type( "four", 4); 18 null += json::object_t::value_type( "A", "a"); 19 null += json::object_t::value_type( "B", "b"); 22 std::cout << object << '\n'; 23 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 -Isrc doc/examples/push_back__object_t__value.cpp -o push_back__object_t__value
- Since
- version 1.0.0
Definition at line 4978 of file json.hpp.
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