CODEWITHSUNDEEP
arraysswiftsortingmultidimensional-array
He Yifei 何一非
He Yifei 何一非

Reputation: 2642

Use sort for multidimensional array (array in array) in Swift?

I want to know that how can we use sort or sorted function for multidimensional array in Swift?

For example theirs an array:

[
    [5, "test888"],
    [3, "test663"],
    [2, "test443"],
    [1, "test123"]
]

And I want to sort it via the first ID's low to high:

[
    [1, "test123"],
    [2, "test443"],
    [3, "test663"],
    [5, "test888"]
]

So how can we do this? Thanks!

Upvotes: 6

Views: 12674

Answers (4)

Mithra Singam
Mithra Singam

Reputation: 2091

Update for Swift 5.0

sort function is renamed to sorted. Here is the new syntax

let sortedArray = array.sorted(by: {$0[0] < $1[0] })

Unlike "sort" function in <= swift4.0, sort function doesn't modify elements in array. Instead, it just returns a new array.

example,

let array : [(Int, String)] = [
    (5, "test123"),
    (2, "test443"),
    (3, "test663"),
    (1, "test123")
]

let sorted = array.sorted(by: {$0.0 < $1.0})
print(sorted)
print(array)


Output:
[(1, "test123"), (2, "test443"), (3, "test663"), (5, "test123")]

[(5, "test123"), (2, "test443"), (3, "test663"), (1, "test123")]

Upvotes: 7

Alireza
Alireza

Reputation: 79

in Swift 3,4 you should use "Compare". for example:

let sortedArray.sort { (($0[0]).compare($1[0]))! == .orderedDescending }

Upvotes: 0

Eric Aya
Eric Aya

Reputation: 70113

You can use sort:

let sortedArray = arr.sort { ($0[0] as? Int) < ($1[0] as? Int) }

Result:

[[1, test123], [2, test443], [3, test663], [5, test123]]

We optionally cast the parameter as an Int since the content of your arrays are AnyObject.

Note: sort was previously named sorted in Swift 1.

No problem if you declare the internal arrays as AnyObject, an empty one won't be inferred as an NSArray:

var arr = [[AnyObject]]()

let sortedArray1 = arr.sort { ($0[0] as? Int) < ($1[0] as? Int) }

print(sortedArray1) // []

arr = [[5, "test123"], [2, "test443"], [3, "test663"], [1, "test123"]]

let sortedArray2 = arr.sort { ($0[0] as? Int) < ($1[0] as? Int) }

print(sortedArray2)  // [[1, test123], [2, test443], [3, test663], [5, test123]]

Upvotes: 16

Kametrixom
Kametrixom

Reputation: 14983

I think you should use an array of tuples, then you won't have any problems with type casts:

let array : [(Int, String)] = [
    (5, "test123"),
    (2, "test443"),
    (3, "test663"),
    (1, "test123")
]

let sortedArray = array.sorted { $0.0 < $1.0 }

Swift is all about type safety

(Change sorted to sort if you're using Swift 2.0)

Upvotes: 4

Related Questions