How to remove value from NSMutableArray - ios

Question

I have a NSMutableArray "coordinates" which gives me values like this
2014-01-11 09:52:15.479 DreamCloud[397:70b] (
{
1000 = {
Linecolor = 0X6495ED;
Lines = "4-s";
Xcord = "77.000000";
Xposition = "54.500000";
Ycord = "111.500000";
Yposition = "51.500000";
};
},
{
1001 = {
Linecolor = 0X6495ED;
Lines = "4-s";
Xcord = "45.000000";
Xposition = "42.500000";
Ycord = "417.000000";
Yposition = "54.000000";
};
},
{
1000 = {
Linecolor = 0X6495ED;
Lines = "4-s";
Xcord = "73.000000";
Xposition = "50.500000";
Ycord = "111.000000";
Yposition = "51.000000";
};
}
)
Within this I need ti remove the values for 1001 and recreate the array without 1001 . How do I do this.I am new in ios so I did not figure out how to do this .
for (NSMutableDictionary *deltag in deletelinearray)
{
NSMutableDictionary *gettagsdeleted = [deltag objectForKey:[NSString stringWithFormat:#"%d",myV.tag]];
NSLog(#"%#",gettagsdeleted);
int starttag=[gettagsdeleted objectForKey:#"Starttag"];
int endtag=[gettagsdeleted objectForKey:#"Endtag"];
}
NSLog(#"%#",coordinates);
Above is the code where in "coordinates " I get the array and start-tags and end-tags are 1000, 1001 . In coordinates I don't know the index as Kumar Kl said .

Answer 1

Consider your array name is coorditates
for (NSDictionary *dict in coorditates) {
if ([dict objectForKey:[NSString stringWithFormat:#"%d",1001]]) {
[coorditates removeObject:dict];
break;
}
}
You can also use NSPredicate but, for that coorditates array must be NSMutableArray
NSPredicate *pred = [NSPredicate predicateWithFormat:#"ANY self.#allKeys != %#", #"1001"];
[coorditates filterUsingPredicate:pred];

Answer 2

Try this for loop instead. Instead of selecting the object with the key it removes it.
for (NSMutableDictionary *deltag in deletelinearray)
{
[coordinates removeObjectForKey:[NSString stringWithFormat:#"%d",myV.tag]];
}

Answer 3

It is not a good coding practice to modify(insert or delete) the items in array while enumerating it. So first find your index and then delete it.
You don't need to create a new array, once the details with "1001" is removed. You already have an update array.
NSString *deleteKey=#"1001";
__block int deleteIndex=-1;
[arr enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
for (NSString *key in [obj allKeys]) {
if([key isEqualToString:deleteKey]){
deleteIndex=idx;
*stop=YES;
}
}
}];
if(deleteIndex>=0){
[arr removeObjectAtIndex:deleteIndex];
}

Answer 4

You want to call the removeObjectAtIndex: function, but it appears your array contains dictionary objects and you want to remove the one with the key 1001. What you want to avoid is removing the object WHILE looping through the array.
So, what I would do is create a variable that will hold the index of the item once you find it, then loop through the array and once you find the object that it matches store the index and break. After, you shouldn't need to recreate the array after you remove the item, removing the object at the index you provide the above function will do just that for you. In your case, you'll want to do the following:
NSString *key = #"1001";
for (NSInteger index = 0; index < array.count; index++) {
NSDictionary *dictionary = coordinates[index];
if (dictionary[key]) {
indexToDelete = index;
break;
}
}
[coordinates removeObjectAtIndex:1001];

Answer 5

int i = 0;
for (NSDictionary *dict in coorditates)
{
if ([dict objectForKey:#"1001"])
{
[coorditates removeObjectAtIndex:i];
}
i++;
}