Book Image

Julia 1.0 Programming. - Second Edition

By : Ivo Balbaert
Book Image

Julia 1.0 Programming. - Second Edition

By: Ivo Balbaert

Overview of this book

The release of Julia 1.0 is now ready to change the technical world by combining the high productivity and ease of use of Python and R with the lightning-fast speed of C++. Julia 1.0 programming gives you a head start in tackling your numerical and data problems. You will begin by learning how to set up a running Julia platform, before exploring its various built-in types. With the help of practical examples, this book walks you through two important collection types: arrays and matrices. In addition to this, you will be taken through how type conversions and promotions work. In the course of the book, you will be introduced to the homo-iconicity and metaprogramming concepts in Julia. You will understand how Julia provides different ways to interact with an operating system, as well as other languages, and then you'll discover what macros are. Once you have grasped the basics, you’ll study what makes Julia suitable for numerical and scientific computing, and learn about the features provided by Julia. By the end of this book, you will also have learned how to run external programs. This book covers all you need to know about Julia in order to leverage its high speed and efficiency for your applications.
Table of Contents (17 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Tuples


A tuple is a fixed-sized group of values, separated by commas and optionally surrounded by parentheses ( ). The type of these values can be the same, but it doesn't have to be; a tuple can contain values of different types, unlike arrays. A tuple is a heterogeneous container, whereas an array is a homogeneous container. The type of a tuple is just a tuple of the types of the values it contains. So, in this sense, a tuple is very much the counterpart of an array in Julia. Also, changing a value in a tuple is not allowed; tuples are immutable.

In Chapter 2, Variables, Types, and Operations, we saw fast assignment, which is made possible by tuples:

// code in Chapter 5\tuples.jl:
a, b, c, d = 1, 22.0, "World", 'x'

 

This expression assigns a value 1, b becomes 22.0, c takes up the value World, and d becomes x.

The expression returns a tuple (1, 22.0,"World",'x'), as the REPL shows as follows:

If we assign this tuple to a variable t1 and ask for its type, we get the following result:

typeof...