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◆ count()
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>
Returns the number of elements with key key. If ObjectType is the default std::map type, the return value will always be 0 (key was not found) or 1 (key was found).
- Note
- This method always returns
0 when executed on a JSON type that is not an object.
- Parameters
-
[in] | key | key value of the element to count |
- Returns
- Number of elements with key key. If the JSON value is not an object, the return value will be
0 .
- Complexity\n Logarithmic in the size of the JSON object.
- Example\n The example shows how
count() is used. \n @includelineno count.cpp \n Output (play with this example @htmlinclude count.link):\n @verbinclude count.output \n The example code above can be translated with @verbatim g++ -std=c++11 -Isrc doc/examples/count.cpp -o count @endverbatim
- Since
- version 1.0.0
Definition at line 4630 of file json.hpp.
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