CODEWITHSUNDEEP
iphoneios6
iPhone Programmatically
iPhone Programmatically

Reputation: 1227

Count how many times each value is repeated in an array

How to check that how many time items are repeated in array. I am having an array that contains repetitive item. Below is array.

"Family:0",
"Family:0",
"Family:0",
"Gold:3",
"Gold:3"

So, i want in response values 3 and 2 for respective items. How can i achieve that. Hope i made my point clear. If any thing not clear please ask.

Below is my code i tried.

int occurrences = 0;
int i=0;
for(NSString *string in arrTotRows){
    occurrences += ([string isEqualToString:[arrTotRows objectAtIndex:indexPath.section]]); //certain object is @"Apple"
    i++;
}

Upvotes: 0

Views: 675

Answers (4)

JAK
JAK

Reputation: 6481

please try this....

int count = 0;

for (int i = 0; i < array.count; ++i) {
    NSString *string = [array objectAtIndex:i];
    for (int j = i+1; j < array.count; ++j) {
        if ([string isEqualToString:[array objectAtIndex:j]]) {
         count++;
        }
    }

Upvotes: 0

Dharmbir Singh
Dharmbir Singh

Reputation: 17535

You can use NSCountedSet for this. Add all your objects to a counted set, then use the countForObject: method to find out how often each object appears.

Example

NSArray *names = [NSArray arrayWithObjects:@"Family:0", @"Family:0", @"Gold:3", @"Gold:3", nil];
    NSCountedSet *set = [[NSCountedSet alloc] initWithArray:names];

    for (id item in set)
    {
        NSLog(@"Name=%@, Count=%lu", item, (unsigned long)[set countForObject:item]);
    }

Output

Name=Gold:3, Count=2

Name=Family:0, Count=2

Upvotes: 2

Daniel Mart&#237;n
Daniel Mart&#237;n

Reputation: 7845

NSCountedSet *countedSet = [[NSCountedSet alloc] initWithArray:yourArray];

For getting the number of occurrences:

int objectCount = [countedSet countForObject:yourQuery];

(where yourQuery is the object whose multiplicity you want to get). In your case, for example:

int objectCount = [countedSet countForObject:@"Family:0"];

and objectCount should be equal to 3 because "Family:0" is three times in the multiset.

Upvotes: 7

jszumski
jszumski

Reputation: 7416

NSCountedSet solves this very problem. Add all of the strings with addObject: and then get the final counts with countForObject: as you enumerate the set.

Upvotes: 0

Related Questions