November 2001
Intermediate to advanced
936 pages
68h 43m
English
Content preview from JavaScript: The Definitive Guide, Fourth 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.
Netscape’s JavaScript 1.2 Incompatibilities
Netscape’s implementation of
JavaScript 1.2 was released (as part of the Netscape 4.0 browser)
while the ECMAScript v1 specification was still being finalized. The
engineers at Netscape made some guesses about what would be in the
specification, and based on those guesses, they made some changes to
the way JavaScript behaved. Because these changes were not compatible
with previous versions of JavaScript, the changes were implemented
only when JavaScript 1.2 was explicitly requested. (In web browsers,
this is done by setting the language attribute of
the HTML <script> tag to
“JavaScript1.2”.) This was an excellent way to introduce
new behavior without breaking old scripts. Unfortunately, when work
on ECMAScript v1 was completed, the new behavior that Netscape
engineers had guessed at was not part of the standard. What this
means is that Netscape’s implementation of JavaScript 1.2 has
special-case behavior that is not compatible with JavaScript 1.1 and
does not conform to the
ECMAScript
specification.
For compatibility with scripts that rely on the nonconforming
behavior of JavaScript 1.2, all future implementations of JavaScript
from Netscape have retained this special behavior when Version 1.2 is
explicitly requested. Note, however, that if you request a version
greater than 1.2 (with a language attribute of “JavaScript1.3”, for example) you will get ECMAScript-compliant behavior. Because this special behavior is present only in JavaScript ...
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.