Sample Shortcut discussed in Episode 430 to create a 500 pixel wide JPG thumbnail from the first page of one or more selected PDFs:

Sample Code to Recap:
Calculate area of circle using variables and print statement:

let radius = 5.0
let pi = 3.14159
let area = pi * (radius * radius)

print("The area of a circle with radius \(radius) is \(area)")

I learned how to simplify that print statement and created a version 1.1:

print("The area of a circle with radius ",radius," is ",area)

What about?

let area = pi * pow(radius,2)

Turns out: To use the pow function, something called the Foundation library (framework) has to be imported to your program.

This library helps you with common programming tasks that aren’t covered by the core Swift language and its standard library

UPDATE!!: Writing pow(radius,2) is an important correction to what I said in the episode!
The area of a circle with radius 5 is most definitely NOT 9817.46875!

SO my improved (1.2) version of the Area of a Circle calculator is:

import Foundation
let radius = 5.0
let pi = 3.14159
let area = pi * pow(radius,2)

print("The area of a circle with radius ",radius," is ",area)