I am getting hex value in string <0000000a>? How can i convert it into integer in objective-c?

Question

First i have to convert Hex but this <> generates an exception when i am trying to convert it to integer

NSString *steps =characteristic.value;
int value2= [steps intValue];

First i have to removce <>, then convert this hexadecimal string into integer value.

print out `characteristic` with NSLog to see what you have. What type of object was assigned to value and what is characteristic? — Volodymyr B., Nov 10 '16 at 09:55
`characteristic.value` is a `NSData` object. So use `NSData` and `getBytes:length:` Do not use `description`, that's bad habits. — Larme, Nov 10 '16 at 09:56
Possible duplicate of [Transform NSData to int in Objective-c](http://stackoverflow.com/questions/25508138/transform-nsdata-to-int-in-objective-c) — Larme, Nov 10 '16 at 09:56
i am getting hexadecimal value <000000ae> which is right, i just want to convert that value from hexadecimal string into integer value — , Nov 10 '16 at 10:00
You should read the `<` with `scanString:intoString:`, and than call `scanHexnt:`. — clemens, Nov 10 '16 at 10:02
"i just want to convert that value from hexadecimal string", it should be a hex NSData, not a hex string. As I said, don't use description. `NSString *steps =characteristic.value;` should throw a warning (putting a `NSData` object into `NSString` object.) — Larme, Nov 14 '16 at 15:20

score 0 · Accepted Answer · answered Nov 10 '16 at 10:03

0

NSString *strVal = [[NSString alloc] initWithData:characteristic.value encoding:NSUTF8StringEncoding]; int intValue = strVal.intValue;

answered Nov 10 '16 at 10:03

Vinay Maheshwari

score -1 · Answer 2 · answered Nov 10 '16 at 10:15

You have to prefix your string with 0x:

NSString *orig = @"000000ae";
NSString *str = [NSString stringWithFormat:@"0x%@" , orig];

to be able to use NSScanner:

unsigned int outVal;
NSScanner* scanner = [NSScanner scannerWithString:str];
[scanner scanHexInt:&outVal];

outVal holds your result now.

2 Answers2