Initilizing a two dimensional array in Swift

Question

I have defined a two dimensional array as :

var monthNames:[[String]]

I want to initialize it as following:

Number of columns: 3, and rows of each column: undefined

so I can init rows later.

Answer 1

As per your question, You are creating array with three columns, each columns will be having more number of rows(records), SO you can do as follows:

var twoDimesions: [[String]] = [[], [], []]

var array1: [String]=[]
array1.append("1 name1")
array1.append("1 name2")
twoDimesions[0] = array1

var array2: [String]=[]
array2.append("2 name1")
array2.append("2 name2")
twoDimesions[1] = array2

println("twoDimentions: \(twoDimesions)")
println("array1: \(array1)")
println("array2: \(array2)")

and you will be getting log as follows:

twoDimentions: [[1 name1, 1 name2], [2 name1, 2 name2], []]
array1: [1 name1, 1 name2]
array2: [2 name1, 2 name2]

This may help you!!!

Answer 2

I presume by undefined you mean empty - so it's an array of 3 elements, where each element is an (empty) array. You can initialize as follows:

var monthNames:[[String]] = [ [], [], [] ]

or:

var monthNames = [[String]](count: 3, repeatedValue: [])

Side note: if you want to initialize the arrays later, remember that you cannot do this:

var array = monthNames[0]
array.append("another test")

because arrays are value types, so when assigned to a variable, a copy of the original array is done. Any change you made is local to that variable, hence not reflected in your original array.