September 2014
Beginner
686 pages
20h 43m
English
Content preview from JavaScript & jQuery: The Missing Manual, 3rd EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 17. Troubleshooting and Debugging
Everybody makes mistakes, but in JavaScript, mistakes can keep your programs from running correctly—or at all. When you first start out with JavaScript, you’ll probably make a lot of mistakes. Trying to figure out why a script isn’t behaving the way it should can be frustrating, but it’s all a part of programming. Fortunately, with experience and practice, you’ll be able to figure out why an error has occurred and how to fix it.
This chapter describes some of the most common programming mistakes, and, more importantly, teaches you how to diagnose problems in your scripts—debug them, as programmers say. In addition, the tutorial will take you step by step through debugging a problematic script.
Top JavaScript Programming Mistakes
There are countless ways a program can go wrong, from simple typos to more subtle errors that only pop up every now and again. However, there are a handful of mistakes that routinely plague beginning (and even advanced) JavaScript programmers. Go over the list in this section, and keep it in the back of your mind when programming. You’ll probably find that knowing these common mistakes makes it a lot easier to identify and fix problems in your own programs.
Non-Closed Pairs
As you’ve noticed, JavaScript is filled with endless parentheses, braces, semicolons, quotation marks, and other punctuation. Due to the finicky nature of computers, leaving out a single punctuation mark can stop a program dead in its tracks. One of ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.