Swift array
Swift Array
An array in Swift, and any other programming language who support arrays, is a list of data. Those data can be any datatype. Integers, double, float, string and even classes. I will just show a few examples here. For a complete list and full documentation I suggest you head over to Apples Swift documentation, by click that link.
Swift array of integers
Say we need a list of integers for our software. Some pre-declared integers in a list of integer constants. Because we dont need to change them. Here is how to do that.
let myIntegers = [1, 3, 5, 10, 25, 100, 1000]
Ok, so how do we use that array of constants? I need to print the first and the last item now.
print(myIntegers[0]) // Printing the first item
print(myIntegers[6]) // Printing the last item
print(myIntegers.last) // Printing the last item
So what if myIntegers was variables instead of constant? And I wanted to change the value of the 1st, 2nd and the last one?
myIntegers[0] = 10 // Changing the first item
myIntegers[1] = 15 // Changing the second item
MyIntegers.last = 99 // Changing the last item
Swift Array – Empty
Seems easy enough. But I need an empty array to populate later in my software. How do I do that?
var myIntegers = [Int]() // Declare an empty array of type Int
So how do I add items to this
myIntegers.append(5) // Your array now contain 1 value. The value 5.
Swift Array – insert
Actually I need to insert a new value before the one I added. Can I do that? Yes.
myIntegers.insert(12, atIndex:0) // The value 12 was inserted at the beginning of the array.
You can use this to insert values where ever you want in the array.
Swift Array – remove
I have a huge array, and I need to remove my 5th value and the last value. Is that even possible? Yes.
myIntegers.removeAtIndex(5)
myIntegers.removeLast()
Swift Array – remove duplicates
My string array that contains html links has a lot of duplicates. Is it possible to remove duplicates easily? Yes it is.
First you convert the array to a Set and then back to an Array. Set doesn’t contain duplicates, since it is not a list like an array. Here is how.
myStringArray = Array(Set(myStringArray)) // Your duplicates are now gone.
Swift Array – default value
Can I declare an array with a default value? I need an array of 10 values with the same value until I change them.
var myDefaultArray = [Double](count: 10, repeatedValue: 5.0)
Thats it for now about array. If you want to learn more and specific situations about array, I suggest you head over to iswift.org.
Happy arraying!
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