What's the answer?

months is an array of integers 1, 2, and 3.

month is one of those integers. So you don't need to access it like a typical array, since 'month' is standing in for the value of that index.

let months = [1, 2, 3]

for month in months {
    if month == 1 {
        println("January")
    } else if month == 2 {
        println("February")
    } else {
        println("March")
    }
}

This may help out: https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/ControlFlow.html

Thanks! I think I get it now. So to make sure I understand how this works.

• month is a variable that refers to the value of the array at whatever index
• the for. . in loop goes sequentially through the values of the array (e.g., months[0], months[1], months[2]. . .) until it goes through the entire array

Does that also mean month is declared implicitly? In this and the other samples of for. . .in loops, the variable after the "for" is never declared.

When it comes to 'month', when you write "for month in months", you are essentially declaring a new constant named month of type Int.

let month: Int

Now, month can be used to reference any of the Int values within the array. Note that month cannot be assigned to any of the integers in the array, only compared (==).