Order an array based on one property

Question

I have a NSMutableArray called allItems which has the following ProductData object.

Each object has cid, cname, ctype and cimage. As you see below json object is not coming in order. However, cid is a indicator for ordering.

I wonder how do you order based on cid?

 [
  {
    "cid": "2",
    "cname": "Meats",
    "ctype": "main",
    "cimage": "baked_chicken.jpg"
  },
  {
    "cid": "1",
    "cname": "Dips",
    "ctype": "side",
    "cimage": "stuffed_eggplant.jpg"
  },
  {
    "cid": "4",
    "cname": "Sandwiches",
    "ctype": "sand",
    "cimage": "chickenshawarma.jpg"
  },
  {
    "cid": "3",
    "cname": "Appetizers",
    "ctype": "side",
    "cimage": "rice_lentils.jpg"
  },
  {
    "cid": "5",
    "cname": "Desserts",
    "ctype": "dsrt",
    "cimage": "cake.jpg"
  }]

If I use the sortDescriptior, it partially works. The issue that I am facing, when it sorts, it first display cid 1 and then cid 10 and then cid 2.

NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid" ascending:YES];
[allItems sortUsingDescriptors:@[sortDescriptor]];

You can use sortDescriptor for this – 3stud1ant3 Aug 22 '17 at 04:03 — 3stud1ant3, Aug 22 '17 at 04:03

vadian · Accepted Answer · 2017-08-22T06:27:16.967

Use a sort descriptor with a comparator passing compare:options: and option NSNumericSearch:

NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid" ascending:YES comparator:^(id obj1, id obj2) {
     return [obj1 compare:obj2 options:NSNumericSearch];
}];

or even simpler:

NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid" ascending:YES selector:@selector(localizedStandardCompare:)];

localizedStandardCompare is a special comparison selector:

This method should be used whenever file names or other strings are presented in lists and tables where Finder-like sorting is appropriate. The exact sorting behavior of this method is different under different locales and may be changed in future releases. This method uses the current locale.

This is the best solution by far. Strings already know how to be sorted, if they contain numeric values. — Amin Negm-Awad, Aug 22 '17 at 05:00

score 1 · Answer 2 · answered Aug 22 '17 at 04:40

Use this

NSSortDescriptor *aSortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid" ascending:YES comparator:^(id obj1, id obj2) {

    if ([obj1 integerValue] > [obj2 integerValue]) {
        return (NSComparisonResult)NSOrderedDescending;
    }
    if ([obj1 integerValue] < [obj2 integerValue]) {
        return (NSComparisonResult)NSOrderedAscending;
    }
    return (NSComparisonResult)NSOrderedSame;
}];
sortedArray = [NSMutableArray arrayWithArray:[unsortedArray sortedArrayUsingDescriptors:@[aSortDescriptor]]];

score 1 · Answer 3 · edited Aug 22 '17 at 05:59

1

NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"cId" 
    ascending:YES selector:@selector(caseInsensitiveCompare:)];

arrToBeSort = [arrToBeSort sortedArrayUsingDescriptors:[NSArray 
    descriptor]];

this will work

edited Aug 22 '17 at 05:59

Vinodh

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answered Aug 22 '17 at 05:52

Nimit

145
1
8

Abdelahad Darwish · Answer 4 · 2017-08-22T04:54:40.833

0

    NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid.intValue" ascending:YES];
[array sortUsingDescriptors:@[sortDescriptor]];

Your "array" has now been sorted after print it

Printing description of array: <__NSArrayM 0x618000041bf0>( { cid = 1; cimage = "stuffed_eggplant.jpg"; cname = Dips; ctype = side; }, { cid = 2; cimage = "baked_chicken.jpg"; cname = Meats; ctype = main; }, { cid = 3; cimage = "rice_lentils.jpg"; cname = Appetizers; ctype = side; }, { cid = 4; cimage = "chickenshawarma.jpg"; cname = Sandwiches; ctype = sand; }, { cid = 5; cimage = "cake.jpg"; cname = Desserts; ctype = dsrt; } )

edited Aug 22 '17 at 04:54

answered Aug 22 '17 at 04:04

Abdelahad Darwish

5,969
1
17
35

It partially works. The issue that I am facing, when it sorts, it first display `cid `1 and then `cid` 10 and then `cid` 2. – casillas Aug 22 '17 at 04:36
Check it and Print Array – Abdelahad Darwish Aug 22 '17 at 04:48
@hotspring why it not work with you – Abdelahad Darwish Aug 22 '17 at 04:50
@ AbdelahadDarwish It will not work when you have different type number like ones, tens,hundreds.It should be same type. – Shabbir Ahmad Aug 22 '17 at 04:59
Just add this sortDescriptorWithKey:@"cid.intValue" – Abdelahad Darwish Aug 22 '17 at 05:03
check again my solution and tell me the result – Abdelahad Darwish Aug 22 '17 at 05:03

Order an array based on one property

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