NSMutableDictionary Key Value Checking Problems

Question

I little confuse in NSMutableDictionary retrieving Key and Value checking for that i did this code.

    NSMutableDictionary *testDictionary=[NSMutableDictionary dictionary];
        //  NSMutableDictionary *testDictionary=[[NSMutableDictionary alloc]init];

        [testDictionary setObject:@"Muhammed Musthafa" forKey:@"10005"];
        [testDictionary setObject:@"Lubaba p" forKey:@"10006"];
        [testDictionary setObject:@"Sahala Banu" forKey:@"10007"];
        [testDictionary setObject:@"Vishnu k" forKey:@"10008"];
        [testDictionary setObject:@"Shabeer PP" forKey:@"10009"];
        [testDictionary setObject:@"Sabeehath " forKey:@"10010"];
        [testDictionary setObject:@"Anusha GS" forKey:@"10011"];
        [testDictionary setObject:@"JINI KS" forKey:@"10012"];
        [testDictionary setObject:@"Athulya T" forKey:@"10013"];
        [testDictionary setObject:@"Midhun KS" forKey:@"10014"];

        for(NSString *kk in testDictionary)
        {
            NSString *fName;
            if(kk==@"10006")
            {
                fName=[testDictionary objectForKey:kk];

            }
            if(kk==@"10007")
            {
                fName=[testDictionary objectForKey:kk];

            }
            if(kk==@"10013")
            {
                fName=[testDictionary objectForKey:kk];
            }
            NSLog(@"KEY=====%@ and  Value====%@",kk,fName);

        }
The out put value :

    2011-11-17 10:49:37.054 ArchiveData[2539:207] KEY=====10013 and  Value====
    2011-11-17 10:49:37.055 ArchiveData[2539:207] KEY=====10006 and  Value====
    2011-11-17 10:49:37.056 ArchiveData[2539:207] KEY=====10008 and  Value====
    2011-11-17 10:49:37.056 ArchiveData[2539:207] KEY=====10010 and  Value====
    2011-11-17 10:49:37.057 ArchiveData[2539:207] KEY=====10012 and  Value====
    2011-11-17 10:49:37.057 ArchiveData[2539:207] KEY=====10014 and  Value====
    2011-11-17 10:49:37.058 ArchiveData[2539:207] KEY=====10005 and  Value====
    2011-11-17 10:49:37.059 ArchiveData[2539:207] KEY=====10007 and  Value====
    2011-11-17 10:49:37.060 ArchiveData[2539:207] KEY=====10009 and  Value====
    2011-11-17 10:49:37.061 ArchiveData[2539:207] KEY=====10011 and  Value====

why this three {(kk==@"10006") if(kk==@"10007") if(kk==@"10013")} if state ment return false?
There is any other method for checking id key like this?
I saw the same type of coding working fine in some other coding,So this is depending any other configuration?
how can i check particular key==@"some Key value"?

I cannot reproduce your problem. There’s probably something else in your code that’s _not_ being shown in the question. — , Nov 17 '11 at 06:50

score 1 · Answer 1 · answered Nov 17 '11 at 05:37

1

You might be better off comparing the strings by using [kk isEqualToString:@"10006"] in order to do a proper string comparison instead of pointer comparisons.

answered Nov 17 '11 at 05:37

Dennis Bliefernicht

5,147
1
28
24

+1 - also, see this link for better explanation of string literal: http://stackoverflow.com/questions/8032375/difference-between-nsstring-literals/8032400#8032400 – bryanmac Nov 17 '11 at 05:43
The same output came when i used [kk isEqualToString:@"10006"]? so thing the problem is some thing else... – Musthafa P P Nov 17 '11 at 05:54

score 0 · Accepted Answer · answered Nov 17 '11 at 07:23

code:

NSMutableDictionary *testDictionary=[NSMutableDictionary dictionary];
    //  NSMutableDictionary *testDictionary=[[NSMutableDictionary alloc]init];

    [testDictionary setObject:@"Muhammed Musthafa" forKey:@"10005"];
    [testDictionary setObject:@"Lubaba p" forKey:@"10006"];
    [testDictionary setObject:@"Sahala Banu" forKey:@"10007"];
    [testDictionary setObject:@"Vishnu k" forKey:@"10008"];
    [testDictionary setObject:@"Shabeer PP" forKey:@"10009"];
    [testDictionary setObject:@"Sabeehath " forKey:@"10010"];
    [testDictionary setObject:@"Anusha GS" forKey:@"10011"];
    [testDictionary setObject:@"JINI KS" forKey:@"10012"];
    [testDictionary setObject:@"Athulya T" forKey:@"10013"];
    [testDictionary setObject:@"Midhun KS" forKey:@"10014"];

    for(NSString *kk in testDictionary)
    {
        NSString *fName;
        if([kk isEqualToString:@"10006"])
        {
            fName=[testDictionary objectForKey:kk];

        }
        if([kk isEqualToString: @"10007"])
        {
            fName=[testDictionary objectForKey:kk];

        }
        if([kk isEqualToString:@"10013"])
        {
            fName=[testDictionary objectForKey:kk];
        }
        NSLog(@"KEY=====%@ and  Value====%@",kk,fName);

    }

output for your code.

2011-11-17 12:47:59.910 test[12512:a0f] KEY=====10008 and  Value====(null)
2011-11-17 12:47:59.910 test[12512:a0f] KEY=====10010 and  Value====(null)
2011-11-17 12:47:59.911 test[12512:a0f] KEY=====10012 and  Value====(null)
2011-11-17 12:47:59.911 test[12512:a0f] KEY=====10014 and  Value====(null)
2011-11-17 12:47:59.912 test[12512:a0f] KEY=====10005 and  Value====(null)
2011-11-17 12:47:59.912 test[12512:a0f] KEY=====10007 and  Value====Sahala Banu
2011-11-17 12:47:59.912 test[12512:a0f] KEY=====10009 and  Value====Sahala Banu
2011-11-17 12:47:59.913 test[12512:a0f] KEY=====10011 and  Value====Sahala Banu
2011-11-17 12:47:59.913 test[12512:a0f] KEY=====10013 and  Value====Athulya T
2011-11-17 12:47:59.913 test[12512:a0f] KEY=====10006 and  Value====Lubaba p

it working fine. After 10007 you dont have condition for for 10009 and 10011. so the fName value is not changed for that.
When you use the == operator, you are comparing pointer values. This will only work when the objects you are comparing are exactly the same object, at the same memory address.

NSMutableDictionary Key Value Checking Problems

2 Answers2