Compare Objective-C const char with NSString

Question

I was wondering if there is a simple way to compare a const char with an NSString, or do I have to convert the const char to an NSString before doing do?

I have been looking through Apple docs but struggling to find an answer to my question.

Is there a reason you don't want to create the NSString? – Carl Norum Feb 28 '13 at 21:23 — Carl Norum, Feb 28 '13 at 21:23

CodaFi · Accepted Answer · 2013-02-28T21:30:42.783

12

Either

NSString *str = @"string";
const char *myChar = "some string";
if (strcmp(myChar,  str.UTF8String))

or

[str isEqualToString:[NSString stringWithUTF8String:myChar]];

The core foundation route is also an option:

CFStringRef myStr = CFSTR("some chars");

bool result = CFStringCompareWithOptions(myStr, ((__bridge CFStringRef)str),CFRangeMake(0,CFStringGetLength(myStr)), kCFCompareCaseInsensitive);

edited Feb 28 '13 at 21:30

answered Feb 28 '13 at 21:24

CodaFi

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Either you meant `strcmp` or you forgot a parameter to `strncmp`. – rmaddy Feb 28 '13 at 21:26
Looks like `if (strcmp(myChar, str.UTF8String))` should be `if (strcmp(myChar, str.UTF8String) == 0)` if you want to check if strings are equal. http://www.cplusplus.com/reference/cstring/strcmp/ – Jaroslav Feb 18 '20 at 09:32

score 4 · Answer 2 · answered Feb 28 '13 at 21:35

4

Better still:

 [str isEqualToString: @(myChar) ];

This is no worse than a cast, which you're bound to need since the types are incommensurable.

answered Feb 28 '13 at 21:35

Mark Bernstein

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Actually, this is miles better than a cast. Only a subset of Core Foundation types can be safely cast back and forth to ObjC objects – CodaFi Feb 28 '13 at 22:43
CodaFi: since I suspected that the original poster came from a C/C++ background, I meant "no worse than a legitimate and safe cast", which is still deprecated but tolerated. (ObjC custom is far more tolerant of casting, because run-time support is better) – Mark Bernstein Mar 01 '13 at 01:24

score 0 · Answer 3 · answered Feb 28 '13 at 21:24

0

You are comparing two different things, so you have to convert one to the other. Which way you convert is up to you.

answered Feb 28 '13 at 21:24

Sebastian

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Compare Objective-C const char with NSString

3 Answers3