search the values in array in iPhone sdk - iphone

Question

I have the array like:
(
{
id=1;
Title="AAAA";
period_id=1;
},
{
id=2;
Title="BBBB";
period_id=2;
},
{
id=3;
Title="CCCC";
period_id=2;
},
{
id=4;
Title="DDDD";
period_id=2;
},
{
id=5;
Title="EEEE";
period_id=3;
},
)
Question: How can i know that Period_id=2 is multiple times in the array?
Help me solve this.
Thank you,

Answer 1

There are lots of ways to do so, Some of them are here ..
A:
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"period_id == %#", #"2"];
NSArray *newArray = [array filteredArrayUsingPredicate:predicate];
NSLog(#"%d", [newArray count]);
B:
NSMutableArray *newArray = [[NSMutableArray alloc] init];
for (id obj in array)
{
if([obj[#"period_id"] isEqualToString:#"2"]){
[newArray addObject:obj];
}
}
NSLog(#"%d", [newArray count]);
C:
NSArray *allIds = [array valueForKey:#"period_id"];
NSCountedSet *set = [[NSCountedSet alloc] initWithArray:allIds];
for (id item in set)
{
NSLog(#"period_id=%#, Count=%d", item,[set countForObject:item]);
}
D:
NSArray *allIds = [array valueForKey:#"period_id"];
__block NSMutableArray *newArray = [[NSMutableArray alloc] init];
NSString *valueToCheck = #"2";
[allIds enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
if([obj isEqualToString:valueToCheck])
[newArray addObject:obj];
}];
NSLog(#"%d", [newArray count]);
E:
NSIndexSet *indexes = [array indexesOfObjectsPassingTest:^(id obj, NSUInteger idx, BOOL *stop) {
return [[obj objectForKey:#"period_id"] isEqualToString:#"2"];
}];
NSArray *newArray = [array objectsAtIndexes:indexes];
NSLog(#"%d", [newArray count]);

Answer 2

try like this,
NSIndexSet *indices = [questionSections indexesOfObjectsPassingTest:^(id obj, NSUInteger idx, BOOL *stop) {
return [[obj objectForKey:#"period_id"] isEqualToString:#"2"];
}];
NSArray *filtered = [questionSections objectsAtIndexes:indices];
NSLog(#"duplictae:%d\n %#",[indices count],filtered);
O/P:-
duplicate: 3
(
{
name = bbbb;
"period_id" = 2;
},
{
name = ccccc;
"period_id" = 2;
},
{
name = ddddd;
"period_id" = 2;
}
)

Answer 3

if the array is sorted, as it seems at your case, just check if the next item has the same value as this one
for(int i = 0; i < array.size() - 1; i++) {
if (array[i].id == array[i + 1].id) {
// Duplicate
}
}
if you just want to know about id = 2
int idCount = 0;
for(int i = 0; i < array.size() - 1; i++) {
if (array[i].id == 2) {
idCount++;
}
}
if you also want to know the location
int idCount = 0;
int idarr[array.size()];
for(int i = 0; i < array.size() - 1; i++) {
if (array[i].id == 2) {
idarr[idCount++] = i;
}
}

Answer 4

I think this is a JSON response from what I gather. Yes you can get the period_id. Add all the period_id's in an NSMutableArray.
Then simply search for the period_id from within this array for the values of the period_id to be same . You will get the index on which the period_id's are same.
NSSet *uniqueElements = [NSSet setWithArray:myArray];
for(id element in uniqueElements) {
// iterate here
}

Answer 5

You could also use NSPredicate to check duplicate.
Try this Example:
NSPredicate *testPredicate = [NSPredicate predicateWithFormat:#"period_id.intValue == %d",value];
NSMutableArray *data = [[NSMutableArray alloc] init];
NSArray *testArray= [yourArray filteredArrayUsingPredicate:testPredicate];
NSLog(#"duplicate:%d",[testArray count]);