Swift by example for loops

# Half-Closed range operator
Defines a range that doesn't
include the last number. 
for index in 1..<5 {
    print(index)           // 1 2 3 4
}

# Closed-Range operator
Defines a range that
includes the last number. 
for index in 1...5 {
    print(index)           // 1 2 3 4 5
}
Traditional for loop. 
for var i = 0; i < 5; i++ {
    print(i)               // 0 1 2 3 4
}