4 Numbers

Numbers are the fundamental language of computers. They are also a staple of software development. Numbers are used to keep track of temperature, determine how many letters are in a sentence, and count the zombies infesting a town. Numbers come in two basic flavors: integers and floating-point numbers.


You have worked with integers already, but we have not yet defined them. An integer is a number that does not have a decimal point or fractional component – a whole number. Integers are frequently used to represent a count of “things,” such as the number of pages in a book. A difference between integers used by computers and numbers you use elsewhere is that an integer type on a computer takes up a fixed ...

Get Swift Programming: The Big Nerd Ranch Guide now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.