distinctUnionOfObjects changes the order of an array

Question

Below is my original array :

{
    FilePath = "Selfcare.jpg";
    ModuleId = 18;
    ModuleName = "Infant N Toddler";
    SkillLevelID = 59;
    SkillLevelName = "Self Care";
},
{
    FilePath = "Preschool.jpg";
    ModuleId = 18;
    ModuleName = "Infant N Toddler";
    SkillLevelID = 60;
    SkillLevelName = "Preschool Readiness";
},
{
    FilePath = "Learning_Primary.jpg";
    ModuleId = 22;
    ModuleName = Cognitive;
    SkillLevelID = 71;
    SkillLevelName = "Learning Readiness - Primary Skills";
},
{
    FilePath = "PreAcad_Primary.jpg";
    ModuleId = 22;
    ModuleName = Cognitive;
    SkillLevelID = 72;
    SkillLevelName = "Pre-Academics: Primary Skills";
}

when I apply distinctUnionOfObjects

NSArray *curriculums = [array valueForKeyPath:@"@distinctUnionOfObjects.ModuleName"];

this changes the order giving me resulting array

<__NSArrayI>(
Cognitive,
Infant N Toddler
)

It should give

<__NSArrayI>(
    Infant N Toddler,
    Cognitive
    )

as per original array order.

How do I restrict this order change?

***it'll give you an array of uniqued values in ModuleName, and you can't guarantee the order to be preserved*** — Anbu.Karthik, Jun 08 '17 at 05:08
Possible duplicate of [How to turn an NSArray of strings into an array of unique strings, in the same order?](https://stackoverflow.com/questions/4209823/how-to-turn-an-nsarray-of-strings-into-an-array-of-unique-strings-in-the-same-o) — Vishnu gondlekar, Jun 08 '17 at 05:14
please try this one NSArray *orderedSet = [[NSOrderedSet orderedSetWithArray:[people valueForKey:@"ModuleName"]] array]; — Birendra, Jun 08 '17 at 05:46
@Vishnugondlekar looping is also the solution. But I will have hundreds of elements into the array. so looping every time is not feasible. Anyway thank u so much for you time too. :) — Krutika Sonawala, Jun 08 '17 at 06:01

score 5 · Accepted Answer · edited Jun 08 '17 at 06:38

5

please try this one

NSArray *orderedSet = [[NSOrderedSet orderedSetWithArray:[people valueForKey:@"ModuleName"]] array];

edited Jun 08 '17 at 06:38

vaibhav

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answered Jun 08 '17 at 05:59

Birendra

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distinctUnionOfObjects changes the order of an array

1 Answers1