Iterating with for loops

Firstly, if we need to perform a loop a specific number of times, we can simply iterate over a range:

for i in 1...10 
{ 
    print(i) 
} 

This loop will then print the numbers 1 up to and including 10.

If we don't explicitly care about how many times a loop takes place, but need to iterate over an entire Array, we can iterate directly over it, using the following syntax:

let arr = [1, 1, 2, 3, 5] 
for i in arr 
{ 
    print(i) 
} 

If we need to know the index of each object in the array, we can apply its enumerated method, which returns to us a sequence of (index, value) tuples:

for (index, i) in arr.enumerated() 
{ 
    print("The value at index \(index) is \(i)") 
} 

A similar syntax exists for Dictionary objects:

let dict = ["a": 1, "b": 2, "c": 3] 
for (letter, position) in dict 
{ 
    print(letter, position) 
} 

We can also iterate over Set objects:

let set:Set = [2,3,5] 
for n in set 
{ 
    print(n) 
} 

If one of those doesn't fulfil your needs, you can always roll your own using while and repeat.