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061c30310e
- API pages for basic_json_document and basic_json_view, one per member, and for the four aliases, each with an example - features/json_view.md: the problem the view solves, ownership and lifetime, what matches basic_json::parse() and what differs, and when to choose json, ordered_json, SAX, or the view - the examples show why one would use the view, not only how: borrowed vs. owned input, reading a few fields and materializing one subtree, reusing a document across many messages - registered in the mkdocs navigation, llms.txt, the docset, the exceptions page (out_of_range.416), architecture.md, the integration page, and the README; the yyjson credit is added to the README and license.md Signed-off-by: Niels Lohmann <mail@nlohmann.me>
1.4 KiB
1.4 KiB
nlohmann::basic_json::is_number
constexpr bool is_number() const noexcept;
This function returns #!cpp true if and only if the JSON value is a number. This includes both integer (signed and
unsigned) and floating-point values.
Return value
#!cpp true if type is number (regardless whether integer, unsigned integer, or floating-point), #!cpp false otherwise.
Exception safety
No-throw guarantee: this member function never throws exceptions.
Complexity
Constant.
Possible implementation
constexpr bool is_number() const noexcept
{
return is_number_integer() || is_number_float();
}
Examples
??? example
The following code exemplifies `is_number()` for all JSON types.
```cpp
--8<-- "examples/is_number.cpp"
```
Output:
```json
--8<-- "examples/is_number.output"
```
See also
- is_number_integer() check if the value is an integer or unsigned integer number
- is_number_unsigned() check if the value is an unsigned integer number
- is_number_float() check if the value is a floating-point number
- basic_json_view::is_number - the same check on a zero-copy view
Version history
- Added in version 1.0.0.
- Extended to also return
#!cpp truefor unsigned integers in 2.0.0.