Replace a value in NSDictionary in iPhone

Question

I have a array (dataArray) of NSDictionary "item". It has datas like "david" for key "name" and "85" for key "marks" etc for 5 students. I want to replace the mark of david to 90 with respect to the array index value (ie 0 for dictionary containing david and 85). How can I do it?

The code for content in array is

[item setobject:name forkey:@"Name"];
[item setobject:mark forkey:@"Marks"];
[dataArray addOject:item]

The above code goes inside parsing, so i have array with 5 objects (students), their name and marks, now I want to replace the mark of the first object in the dataArray.

score 74 · Accepted Answer · edited Dec 21 '10 at 17:22

74

Here's what you can do:

NSMutableDictionary *newDict = [[NSMutableDictionary alloc] init];
NSDictionary *oldDict = (NSDictionary *)[dataArray objectAtIndex:0];
[newDict addEntriesFromDictionary:oldDict];
[newDict setObject:@"Don" forKey:@"Name"];
[dataArray replaceObjectAtIndex:0 withObject:newDict];
[newDict release];

Hope this helps!

edited Dec 21 '10 at 17:22

Warrior

39,156
44
139
214

answered Dec 21 '10 at 16:57

donkim

13,119
3
42
47

changed objectForIndex to objectAtIndex.Thanks – Warrior Dec 21 '10 at 17:23

score 30 · Answer 2 · edited Dec 21 '10 at 16:19

30

You first need an NSMutableDictionary with it you can change the key and value.

It would be like this:

NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"david", @"name", "85", @"marks", nil];

[dict setObject:@"90" forKey:@"david"];

edited Dec 21 '10 at 16:19

jer

20,094
5
45
69

answered Dec 21 '10 at 16:16

vodkhang

18,639
11
76
110

I gave David as example, i am getting these values after parsing, so how can give that value as static? – Warrior Dec 21 '10 at 16:35
3

This is simple and better answer – Sam B Oct 21 '13 at 15:29

score 12 · Answer 3 · answered Apr 01 '15 at 13:20

12

 // NSDictionary *dict = ...
    NSMutableDictionary *mutableDict = [dict mutableCopy];
    [mutableDict setObject:@"myObject" forKey:@"myKey"];
    dict = [mutableDict mutableCopy];

I hope it helps

answered Apr 01 '15 at 13:20

Zsivics Sanel

1,047
1
15
17

score 10 · Answer 4 · answered Aug 17 '12 at 21:36

If you want to update an object in a NSDictionary you should use NSMutableDictionary instead. NSMutableDictionary has the following EXTRA methods

Adding Entries

setObject:forKey:
setValue:forKey:
addEntriesFromDictionary:
setDictionary:

Removing Entries

removeObjectForKey:
removeAllObjects
removeObjectsForKeys:

score 1 · Answer 5 · answered Dec 21 '10 at 16:18

1

[davidsRecord setObject:@"100" forkey:@"mark"];

answered Dec 21 '10 at 16:18

mmccomb

13,516
5
39
46

Replace a value in NSDictionary in iPhone

5 Answers5

Linked

Related