Q:

Map Function in Swift

I am working with the map function in Swift.  I am seeing use of "$0" and do not know what it means.  Is the "$0" a pointer to the current element of the array?  
stringArray = newStringArray.map({"\($0)New"})

A:

I wouldn't use the word pointer, but I think you have the right idea. When you use map here, you're taking an array and applying a function to every element in that array. Here, the function takes in one argument (a string) and outputs another string. $0 refers to the first argument to the function you're calling which, in this case, is the only argument.
The anonymous sort of functions you pass to map are called closures. Looking at Apple's official documentation on closures might be helpful! Here's a link: https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Closures.html

