parsing NSString to Double
objective-c
Solution
You can use the `NSScanner` class:
NSString *s = @"1.5e5";
NSScanner *scanner = [NSScanner scannerWithString:s];
double d;
BOOL success = [scanner scanDouble:&d];
If you want to ensure that the entire string has been scanned (no extra characters after the number), use
BOOL isAtEnd = [scanner isAtEnd];
Problem
so I want to convert `NSString` to double. I found the following example: ``` NSString * s = @"1.5e5"; NSLog(@"%lf", [s doubleValue]); ``` It works but if `doubleValue` cannot convert the string to double it simply returns 0.0 which is not what I need. I need some method that tries to convert a string representation of double to double and if indicate somehow if it can't be converted. c# has an excellent method ``` double d; boolean Double.TryParse(str, out d) ``` Is there any method similar to the above one in Objective C? or maybe it's better to use regex? however, i don't really know how to do that.