CODEWITHSUNDEEP
objective-c
tesla
tesla

Reputation: 77

parsing NSString to Double

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.

Upvotes: 3

Views: 3729

Answers (1)

Martin R
Martin R

Reputation: 539685

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];

Upvotes: 9

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