freeCodeCamp/guide/english/swift/arrays/index.md

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Arrays

Arrays

Arrays are a collection type that stores elements of the same type in an ordered list.

Initialization

//create immutable array.
let oddNumbers: [Int] = [1,3,5,7,9];
let evenNumbers = [2,4,6,8];

//create an empty mutable array
var numbers = [Int]();

Modification

Add a single element to an array

let someNumber = 0
numbers.append(someNumber)

Add multiple elements to an array

numbers += oddNumbers
numbers.append(contentsOf: evenNumbers)

Remove and Insert at Index

//remove element from an array at index
let removedInt = numbers.remove(at: 4)
//insert element at specific index
numbers.insert(removedInt, at: 4)

Iteration

You can iterate over a set using a for-in loop. Below are two different ways to do essentially the same thing.

var showNumbers = ""
numbers = numbers.sorted() //sort the numbers in ascending order
for i in 0..<numbers.count {
    showNumbers += "\(numbers[i]) "
}
print(showNumbers);

showNumbers = ""
for i in numbers {
    showNumbers += "\(numbers[i]) "
}
print(showNumbers);

The output(s) for the above are "0 1 2 3 4 5 6 7 8 9"

More Information:

• Arrays