How could we cast the following array into an NSArray that accesses the NSArray method:
componentsJoinedByString() < let arr = ["1", "2", "3"]

What set of keywords is most commonly used to iterate over a collections of items?

How can we use optional binding to determine if the variable string is not nil?

Choose the answer that declares an optional closure.

Let’s assume "numbers" is an array of unsorted integers. Which of these could be used to sort numbers?

How could you call the following function that takes a closure as an argument using trailing closure syntax: ()) { // function body goes here }>

What is the typical byte width of Float data type in Swift?

Weak references are declared as _____ types

unowned reference types are declared as __

'NSOperationQueue.mainQueue().addOperationWithBlock' will add the operation to

GCD provides the following types of Queues: