Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "The preceding code has shown us the fact that an instance of ChildClass passes as an instance of all of its parent items all the way up the inheritance tree."

A block of code is set as follows:

{
  "php": ">=7.0.0",
  "egulias/email-validator": "^2.0|^3.1",
  "symfony/polyfill-iconv": "^1.0",
  "symfony/polyfill-mbstring": "^1.0",
  "symfony/polyfill-intl-idn": "^1.10"
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

<?php
declare(strict_types=1);
namespace Book\Part3\Chapter8\ToyMVC\View\Data;
interface TemplateDataInterface
{
}

Any command-line input or output is written as follows:

cd /my/project/root/directory
composer init

Bold: Indicates a new term, an important word, or words that you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: "It's very easy to remove a package from Packagist. Simply click the red Delete button."

Tips or important notes

Appear like this.