double primitive value from an array directly.
- macOS 10.7+
- Mac Catalyst 13.0+Beta
The array which is to be examined.
The index of the value to obtain. This value must lie within the index space of the array (0 to N-1 inclusive, where N is the count of the array). If the index is outside that range, the behavior is undefined.
double value at the specified index. NAN if the value at the specified index is not a floating point value.