Sorting Array issue in iOS app

Question

I have an array like:

( "8461.86","8468.22","8468.22","8162.59","8164.50","7280.59" )

I try to sort this array decendingly as per following:

sortedArray = [arr_distance sortedArrayUsingComparator:^(id firstObject, id secondObject) {
    return [((NSString *)firstObject) compare:((NSString *)secondObject) options:NSNumericSearch];
}];

But i got following array like:

( "7280.59","8162.59","8164.50","8461.86","8468.22","8468.22" )

Why this happen?

I also try with like

return [firstObject compare:secondObject options:NSNumericSearch];

But not getting proper sorted array.

The sort you provided is sorting in ascending order. This is the default. — rmaddy
– rmaddy, Commented Apr 16, 2013 at 6:31

Manu · Accepted Answer · 2013-04-16 06:53:08Z

2

NSSortDescriptor *desc = [[NSSortDescriptor alloc]initWithKey:@"" ascending:NO];
NSMutableArray *yourTempArray = [[NSMutableArray alloc]initWithObjects:@"8459.93",@"8466.28",@"8466.28",@"8160.70",@"8162.61",@"7278.56", nil];
[yourTempArray sortUsingDescriptors:[NSArray arrayWithObject:desc]];
NSLog(@"sotedAr == %@",yourTempArray);

Output:

sotedAr == (
"8466.28",
"8466.28",
"8459.93",
"8162.61",
"8160.70",
"7278.56"

)

edited Apr 16, 2013 at 6:53

answered Apr 16, 2013 at 6:31

Manu

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5 Comments

HARSH AGRAWAL Over a year ago

Thanks for your reply! But my values can be repeated i.e. same value can repeated more than once.

Manu Over a year ago

So what ? It gives you in the sorted list rite? For Ex: 5,6,7,8,5 then output comes as 8,7,6,5,5 rite ?

HARSH AGRAWAL Over a year ago

thanks for your reply! But when i give array like: NSMutableArray *yourTempArray = [[NSMutableArray alloc]initWithObjects:@"8459.93",@"8466.28",@"8466.28",@"8160.70",@"8162.61",@"7278.56", nil]; It is not properly sorted

Manu Over a year ago

dude don't copy and paste your objects. See the output and i got the output as above

HARSH AGRAWAL Over a year ago

sorry i made some mistake that's why i didn't get proper array

ganzogo · Accepted Answer · 2013-04-16 06:36:36Z

2

To sort in descending order, you could just switch the firstObject and secondObject in your code:

sortedArray = [arr_distance sortedArrayUsingComparator:^(id firstObject, id secondObject) {
  return [((NSString *)secondObject) compare:((NSString *)firstObject) options:NSNumericSearch];
}];

answered Apr 16, 2013 at 6:36

ganzogo

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Comments

Sunil Zalavadiya · Accepted Answer · 2013-04-16 06:41:23Z

1

Try following code:-

NSSortDescriptor *frequencyDescriptor = [NSSortDescriptor sortDescriptorWithKey:@""
                                                               ascending:NO
                                                              comparator:^(id obj1, id obj2) {
                                                                  return [obj1 compare:obj2 options:NSNumericSearch];
                                                              }];
NSEnumerator * enumerator = [arr_distance objectEnumerator];
NSArray * descriptors = [NSArray arrayWithObjects:frequencyDescriptor, nil];
NSArray * sortedArray =   [arr_distance sortedArrayUsingDescriptors:descriptors];
enumerator = [sortedArray objectEnumerator];
NSLog(@"sortedArray = %@",sortedArray);

// use sortedArray which is sorted

answered Apr 16, 2013 at 6:41

Sunil Zalavadiya

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2 Comments

HARSH AGRAWAL Over a year ago

Thanks for Your Reply! But not get properly sorted array. I have distance array like:("8459.93","8466.28","8466.28","8160.70","8162.61","7‌278.56")

HARSH AGRAWAL Over a year ago

sorry, you are right. Due my mistake i didn't get proper array. I like to give up vote but due to low Reputation, I can't do it. Sorry once again...

Nazik · Accepted Answer · 2013-04-16 07:02:33Z

1

Below code may be useful for sorting your array in descending order

NSArray *arr = [NSArray arrayWithObjects:@"8459.93",@"8466.28",@"8466.28",@"8160.70",@"8162.61",@"7278.56", nil];
NSMutableArray *yourTempArray = [[NSMutableArray alloc]init];
[yourTempArray addObjectsFromArray:arr];
NSLog(@"before sorting = %@",yourTempArray);
NSSortDescriptor* sort = [NSSortDescriptor sortDescriptorWithKey: @"self" ascending: NO];

[yourTempArray sortUsingDescriptors:[NSArray arrayWithObject:sort]];
NSLog(@"After sorting = %@",yourTempArray);

edited Apr 16, 2013 at 7:02

answered Apr 16, 2013 at 6:29

Nazik

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4 Comments

HARSH AGRAWAL Over a year ago

Thanks for your reply! But i am not getting the sorted array.

Nazik Over a year ago

@user2243212,Did u tried that code, it will surely sort the arrray in descending order

Nazik Over a year ago

@user2243212, just copy and paste the above code in your project's viewdidload function , run the project and see the output

HARSH AGRAWAL Over a year ago

sorry, you are right. Due my mistake i didn't get proper array. I like to give up vote but due to low Reputation, I can't do it. Sorry once again..

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