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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>
add an object to an array Appends the given element val to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending val.
- Parameters
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[in] | val | the value to add to the JSON array |
- Exceptions
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std::domain_error | when called on a type other than JSON array or null; example: "cannot use push_back() with number" |
- Complexity
- Amortized constant.
- Example
- The example shows how
push_back() and += can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array. 8 json array = {1, 2, 3, 4, 5}; 12 std::cout << array << '\n'; 13 std::cout << null << '\n'; 22 std::cout << array << '\n'; 23 std::cout << null << '\n'; basic_json<> json default JSON class
Output (play with this example online): [1,2,3,4,5]
null
[1,2,3,4,5,6,7]
["first","second"]
The example code above can be translated withg++ -std=c++11 -Isrc doc/examples/push_back.cpp -o push_back
- Since
- version 1.0.0
Definition at line 4914 of file json.hpp.
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