Change string to integer in Objective-C

Question

Possible Duplicate:
How do I convert a string into an integer in objective C?

I want to take a string from an UITextField object and convert it into an integer scalar type.

NSInteger *ageOfTheUser;
NSString *string;
self.string=age.text;
ageOfTheUser=(int)string;

I am getting a warning at ageOfTheUser with 'assigment makes pointer from string cast'.

I think you want `NSInteger ageOfTheUser;`; no `*`. – Williham Totland Dec 09 '11 at 19:05 — Williham Totland, Dec 09 '11 at 19:05

score 4 · Accepted Answer · answered Dec 09 '11 at 19:02

If your string is already set to a number, you can simply do:

ageOfTheUser = [string integerValue];

and you're all set.

There's a difference between intValue (which is meant to go to a type of int) and integerValue (which goes to your declared type of NSInteger).

One more thing, get rid of the pointer after your NSInteger declaration (i.e. instead of NSInteger * ageOfTheUser;, do NSInteger ageOfTheUser;).

Duncan Babbage · Answer 2 · 2011-12-09T19:13:57.667

2

ageOfTheUser = [string intValue];

Note you can assign an int to an NSInteger without any additional syntax.

edited Dec 09 '11 at 19:13

answered Dec 09 '11 at 19:02

Duncan Babbage

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this isn't correct because NSString's intValue method returns an `int`, not a `NSInteger` – Michael Dautermann Dec 09 '11 at 19:13
Really? Have you tried this and found that it does not work? :) – Duncan Babbage Dec 09 '11 at 19:18
Oh sure, it does work (for 32-bit number/architecture). 64-bit is somewhat different. [Here's a related question that you may find illuminating](http://stackoverflow.com/questions/5870867/why-is-there-an-nsinteger) and [another one](http://stackoverflow.com/questions/4445173/when-to-use-nsinteger-vs-int). – Michael Dautermann Dec 09 '11 at 19:25

score 2 · Answer 3 · edited Dec 09 '11 at 19:04

2

Simple as this:

int myAgeInt = [@"30" intValue];

edited Dec 09 '11 at 19:04

Williham Totland

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answered Dec 09 '11 at 19:02

Louie

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You don't need the stringWithFormat in the middle. – StilesCrisis Dec 09 '11 at 19:04

score 1 · Answer 4 · answered Dec 09 '11 at 19:05

1

First of all NSInteger is typedef'd to long int, so it's not an object. Just use:

NSInteger ageOfTheUser;

Converting NSString to int is very simple:

ageOfTheUser = [self.string intValue];

answered Dec 09 '11 at 19:05

Sanjay Chaudhry

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Change string to integer in Objective-C

4 Answers4