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

Strings


Literal strings are always of type String:

julia> typeof("hello")
String

This is also true if they contain UTF-8 characters that cannot be represented in ASCII, as in this example:

julia> typeof("Güdrun")String

UTF-16 and UTF-32 are also supported. Strings are contained in double quotes (" ") or triple quotes (""" """). They are immutable, which means that they cannot be altered once they have been defined:

julia> s = "Hello, Julia"
julia> s[2] = 'z'
ERROR: MethodError: no method matching setindex!(::String, ::Char, ::Int64)

String is a succession, or an array of characters (see the Ranges and arrays section) that can be extracted from the string by indexing it, starting from1: with str = "Julia"str[1] returns the character 'J', and str[end] returns the character 'a', the last character in the string. The index of the last byte is also given by endof(str), and length() returns the number of characters. These two are different if the string contains multi-byte Unicode characters...