1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37
|
### jsoncons::basic_json::get_value_or
```cpp
template <typename T,typename U>
T get_value_or(const string_view_type& name, U&& default_value) const;
```
Returns a value in a basic_json object
if `name` matches the name of a member,
otherwise returns a default value.
Throws `std::domain_error` if not an object or null value.
### Type requirements
- `T` must meet the requirements of [CopyConstructible](https://en.cppreference.com/w/cpp/named_req/CopyConstructible)
- `U` must be convertible to `T`
### Examples
#### Return a value if available, a default value if not
```cpp
#include <jsoncons/json.hpp>
int main()
{
json j(json_object_arg, {{"author","Evelyn Waugh"},{"title","Sword of Honour"}});
std::cout << j.get_value_or<std::string>("author","unknown") << "\n";
std::cout << j.get_value_or<std::string>("category","fiction") << "\n";
}
```
Output:
```
Evelyn Waugh
fiction
```
|