Returns an approximation of the specified font's weight.
- macOS 10.0+
The font whose approximate weight is returned.
An approximation of the weight of the given font, where 0 indicates the lightest possible weight, 5 indicates a normal or book weight, and 9 or more indicates a bold or heavier weight. Because this method returns only an approximation of a font's weight, it is not guaranteed to return the exact weight with which
font was initialized.