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Professional JavaScript for Web Developers

You're reading from   Professional JavaScript for Web Developers Discover an easy-to-learn guide to upgrade your JavaScript skills

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Product type Paperback
Published in Nov 2019
Publisher Wiley
ISBN-13 9781119366447
Length 1144 pages
Edition 4th Edition
Languages
Tools
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Author (1):
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Matt Frisbie Matt Frisbie
Author Profile Icon Matt Frisbie
Matt Frisbie
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Table of Contents (37) Chapters Close

COVER FREE CHAPTER
FOREWORD
INTRODUCTION 1 What Is JavaScript? 2 JavaScript in HTML 3 Language Basics 4 Variables, Scope, and Memory 5 Basic Reference Types 6 Collection Reference Types 7 Iterators and Generators 8 Objects, Classes, and Object-Oriented Programming 9 Proxies and Reflect 10 Functions 11 Promises and Async Functions 12 The Browser Object Model 13 Client Detection 14 The Document Object Model 15 DOM Extensions 16 DOM Levels 2 and 3 17 Events 18 Animation and Graphics with Canvas 19 Scripting Forms 20 JavaScript APIs 21 Error Handling and Debugging 22 XML in JavaScript 23 JSON 24 Network Requests and Remote Resources 25 Client-Side Storage 26 Modules 27 Workers 28 Best Practices A ES2018 and ES2019 B Strict Mode C JavaScript Libraries and Frameworks D JavaScript Tools INDEX
END USER LICENSE AGREEMENT

XPATH SUPPORT IN BROWSERS

XPath was created as a way to locate specific nodes within a DOM document, so it's important to XML processing. An API for XPath wasn't part of a specification until DOM Level 3, which introduced the DOM Level 3 XPath recommendation. Many browsers chose to implement this specification, but Internet Explorer decided to implement support in its own way.

DOM Level 3 XPath

The DOM Level 3 XPath specification defines interfaces to use for evaluating XPath expressions in the DOM. To determine if the browser supports DOM Level 3 XPath, use the following JavaScript code:

let supportsXPath = document.implementation.hasFeature("XPath", "3.0");

Although there are several types defined in the specification, the two most important ones are XPathEvaluator and XPathResult. The XPathEvaluator is used to evaluate XPath expressions within a specific context. This type has the following three methods:

  • createExpression(expression, nsresolver )&...
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