Datasheet

Chapter 1: Introduction to JavaScript
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What we are seeing in the browser engines lately is new emphasis on the raw performance of the
JavaScript interpreter – – something not considered a major issue before. This is the natural outcome of
an increasing reliance on JavaScript - rich web applications. They are achieving this in part by treating the
interpreter as a compiler of sorts and running highly sophisticated analysis on the code to generate
the most concise byte - code possible. The result is an interpreted JavaScript application with performance
approaching that of native compiled code.
In Figure 1 - 5 you can see how Safari (WebKit) JavaScript performance has improved lately.
35000
SunSpider JavaScript Performance
30000
25000
20000
15000
10000
5000
0
Chrome
Beta 1
Safari 4.0 Firefox
3.1 (no
tracing)
Firefox
3.0.1
Safari
3.1.2
Opera
9.5.2
IE8 Beta
2
IE7
Time (ms) - Smaller is better
Figure 1-4
70
60
50
40
30
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10
0
Webkit 3.0 Webkit 3.1 Squirrelfish
Safari Performance Benchmark Score
Squirrelfish
Extreme
Score (Higher is Better)
Figure 1-5
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