How to compare string objects in objective-c?

Question

Actually I want to populate an array to fill up my table view, but the problem is I have to compare two strings and if they match I wanted to add that string in the array. Here is my code:

for (NSDictionary *item in facilityZoneData) {
    NSString *zoneFacilityID = [NSString stringWithFormat:@"%@",[item objectForKey:@"FacilityId"]]; 

    if ([detailFacility isEqualToString:zoneFacilityID ]) {
        NSLog(@"object added");
    }
}

The detailFacility is NSString object which is declared in the header file. The problem is it is not at all comparing the string. I know that there are surely some values which are equal. tell me if I am missing something

What do you get if you add NSLog(@"#%@# #%@#", zoneFacilityID, detailFacility ); before your if() statement? Maybe there are some trailing spaces in one of the two? — Paolo Stefan
– Paolo Stefan, Commented Apr 2, 2012 at 15:46
Likely some difference in formatting -- blanks on the end, etc. Use NSLog thusly: NSLog(@"zoneFacilityId = >>>%@<<<, detailFacility = >>>%@<<<", zoneFacilityId, detailFacility); in order to detect any characters tacked on the ends. — Hot Licks
– Hot Licks, Commented Apr 2, 2012 at 15:47
Basically detailFacility is populated from another view controller and the it is showing up correct in NSLog, but I don't get why the comparison is not successful as there is surely matching string at some index — Hassam
– Hassam, Commented Apr 2, 2012 at 15:53
Have you tried running this in the debugger with a breakpoint set on the if statement? — JeremyP
– JeremyP, Commented Apr 2, 2012 at 15:55
Yes I have tried it with breakpoints but it seems like that it never executes the statements in the if-condition. — Hassam
– Hassam, Commented Apr 2, 2012 at 16:00

Mario · Accepted Answer · 2012-04-02 15:49:21Z

3

Your question is not clear. To compare strings you use

NSString isEqualToString: NSString

Like you did. Before your if-statement NSLog the detailFacility and zoneFacilityID objects to see what they contain. Cheers

answered Apr 2, 2012 at 15:49

Mario

4,5201 gold badge23 silver badges32 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

skytz · Accepted Answer · 2012-04-02 16:37:09Z

-2

yea..i had the same problem a few days ago

i made a work-around. Do this:

if ([detailFacility UTF8String] == [zoneFacilityID UTF8String] ){ ...}

for some reason nsstring compassion is comparing addresses and pointers...try this and tell me if it works

i dont know why but that works for me :/

if it doesnt work..just use c function:

if(!strcmp([detailFacility UTF8String],[zoneFacilityID UTF8String])){
<are equal>
}else{
<aren't equal>
}

edited Apr 2, 2012 at 16:37

answered Apr 2, 2012 at 16:10

skytz

2,2012 gold badges18 silver badges24 bronze badges

4 Comments

bbum Over a year ago

"I don't know why, but that works for me." is never the right answer; you are just pushing off a bug until later and, worse, building up a ton of code that assumes the broken code is behaving correctly.

skytz Over a year ago

ok..so after 10 min of brain stupidity on my part..i finally figured it out. I'm comparing c++ strings in my code ...not c strings , that's why it works ...so..my bad...but the c comparison works, i tested it

bbum Over a year ago

That doesn't make the C comparison code correct, though... converting to a UTF8String, then doing strcmp() is about as inefficient as possible....

skytz Over a year ago

well..it was an idea...i'm not saying its the best idea ever but it works.Its like this: you either wait a few hours to fix a problem like this or you use an inefficient way and come back later when you figured out what is wrong (or at least thats how i think)

Collectives™ on Stack Overflow

How to compare string objects in objective-c?

2 Answers 2

Comments

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related