Swift Programming: The Big Nerd Ranch Guide

Operations on Integers

Swift allows you to perform basic mathematical operations on integers using the familiar operators + (add), - (subtract), and * (multiply). Try printing the results of some arithmetic.

Listing 4.8  Performing basic operations

...
let numberOfPeople: UInt = 40
let volumeAdjustment: Int32 = -1000

print(10 + 20)
print(30 - 5)
print(5 * 6)

The compiler respects the mathematical principles of precedence and associativity, which define the order of operations when there are multiple operators in a single expression. For example:

Listing 4.9  Order of operations

...
print(10 + 20)
print(30 - 5)
print(5 * 6)

print(10 + 2 * 5) // 20, because 2 * 5 is evaluated first
print(30 - 5 - 5) // 20, because 30 ...