Returns the primary
double value represented by a string.
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
- Core Foundation
A string that represents a double value. The only allowed characters are the ASCII digit characters (ASCII
0x39), the plus sign (ASCII
0x2B), the minus sign (ASCII
0x2D), and the period character (ASCII
double value represented by
0 if there is a scanning error (if the string contains disallowed characters or does not represent a double value).
Consider the following example:
val in this example would contain the value
0 after the function is called.