getTime() - start;
document.write( ???String concat method: ??? + duration + ??? < /br > ??™);
}
Chapter 9: Bandwidth and Performance Optimizations
219
function intermStringTable(){
var start = new Date().getTime();
var buf = ??? < table > ???;
for (var i=0; i < 10000;i++){
var row = ??? < tr > ???;
for (var j=0;j < 40;j++){
row += ??? < td > < i > ??? + ???content??? + ??? < /i > < /td > ???;
}
row += ??? < /tr > ???;
buf += row
}
buf += ??? < /table > ???;
var duration = new Date().getTime() - start;
document.write(???Intermediate concat method: ??? + duration + ??? < /br > ??™);
}
< /script >
< body >
< /body >
< script type=???text/javascript??? language=???javascript??? >
stringTable();
intermStringTable();
< /script >
< /html >
What to Do and Not to Do
You will want to be sure to avoid with statements, which slow down the processing of the related code
block. In addition to the fact that with is inefficient, it has also been depreciated in the JavaScript standard.
Second, avoid using eval() in your scripts. It is very expensive from a performance standpoint.
Besides, you should be able to develop a more efficient solution rather than resorting to eval() .
Comments add to readability and manageability, but be wise in their usage.
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