How to sort an array in iOS? - ios

Question

i am newbie in iOS Development. My array Contain Dictionary Value Key like as
for(NSDictionary *dict in self.imageArray )
{
[self.imagesa addObject:#{#"demopage":[dict valueForKey:#"demopage"]}];
}
Here my "demoPage" Key Value Contain Two Key like as "link" and "Pageno" here link contain my ImageURL and "pageno" contain page number like as
-demopage
{
link:"URL",
page_no: "12"
},
{
link:"URL",
page_no: "13"
},
{
link: "URL",
page_no: "14"
},
{
link: "",
page_no: "3"
},
{
link:"URL",
page_no: "31"
},
{
link: "URL",
page_no: "32"
},
When i parsed it then i get data in This range like as 12,13,14,3,31,32 i want to arrange this image like as page number based i want it like as 1,2,3 up to data array.

Answer 1

For some reason you are storing the page number as a string and not a number. So a simple sort will sort it alphabetically.
i.e. 1, 10, 11, 12, 2, 20, 21, 235, 3, 35, 4
You need it to sort alphanumerically which you can do like this...
NSSortDescriptor *alphaNumSD = [NSSortDescriptor sortDescriptorWithKey:#"page_no" ascending:YES comparator:^(NSString *string1, NSString *string2) {
return [string1 compare:string2 options:NSNumericSearch];
}];
NSArray *sortedArray = [self.theArrayYouWantToSort sortedArrayUsingDescriptors:#[alphaNumSD]];
Example
NSArray *originalArray = #[
#{#"page_no": #"27"},
#{#"page_no": #"1"},
#{#"page_no": #"12"},
#{#"page_no": #"23"},
#{#"page_no": #"3"},
#{#"page_no": #"2"},
#{#"page_no": #"17"},
];
NSSortDescriptor *alphaNumSD = [NSSortDescriptor sortDescriptorWithKey:#"page_no"
ascending:YES
comparator:^(NSString *string1, NSString *string2)
{
return [string1 compare:string2 options:NSNumericSearch];
}];
NSArray *sortedArray = [originalArray sortedArrayUsingDescriptors:#[alphaNumSD]];
NSLog(#"%#", sortedArray);
Output
(
{
"page_no" = 1;
},
{
"page_no" = 2;
},
{
"page_no" = 3;
},
{
"page_no" = 12;
},
{
"page_no" = 17;
},
{
"page_no" = 23;
},
{
"page_no" = 27;
}
)
It definitely works as expected.

Answer 2

NSArray *ordersArray = info[#"result"];
NSArray *properSortedArray = [ordersArray sortedArrayUsingComparator:
^(id obj1, id obj2)
{
NSInteger value1 = [[obj1 objectForKey: #"orderId"] intValue];
NSInteger value2 = [[obj2 objectForKey: #"orderId"] intValue];
if (value1 > value2)
{
return (NSComparisonResult)NSOrderedAscending;
}
if (value1 < value2)
{
return (NSComparisonResult)NSOrderedDescending;
}
return (NSComparisonResult)NSOrderedSame;
}];

Answer 3

Try:
[self.dataArray sortedArrayUsingDescriptors:#[[NSSortDescriptor sortDescriptorWithKey:#"page_no" ascending:YES]]]