How to convert a string into double and vice versa?

objective-c
rksprst picture rksprst · Oct 4, 2008 · Viewed 277.1k times · Source

I want to convert a string into a double and after doing some math on it, convert it back to a string.

How do I do this in Objective-C?

Is there a way to round a double to the nearest integer too?

Answer

olliej picture olliej · Oct 4, 2008

You can convert an NSString into a double with 

double myDouble = [myString doubleValue];

Rounding to the nearest int can then be done as

int myInt = (int)(myDouble + (myDouble>0 ? 0.5 : -0.5))

I'm honestly not sure if there's a more streamlined way to convert back into a string than

NSString* myNewString = [NSString stringWithFormat:@"%d", myInt];

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