Hi, thanks fort his little optimization tutorial :-)
One question, is there a difference between a loop with a running variable (e.g. for (i=0; i<rows.length; i++) ) and a for-in loop (e.g. for (var i in rows) )? I've done some tests and couldn't find any performance difference beside the normal variation between two different measurements. Which variant should be preferred? by(e) Stephan 2009/2/6 jQuery Lover <ilovejqu...@gmail.com>: > > That is true.... > > I always suggest using built in for() loop with huge data sets... and > people keep ignoring me :))) > > ---- > Read jQuery HowTo Resource - http://jquery-howto.blogspot.com > > > > On Fri, Feb 6, 2009 at 8:25 AM, Michael Geary <m...@mg.to> wrote: >> >> "...there is not much room for improvement left." >> >> You just know that when you say that, someone will come along with a 20x-40x >> improvement. ;-) >> >> http://mg.to/test/loop1.html >> >> http://mg.to/test/loop2.html >> >> Try them in IE, where the performance is the worst and matters the most. >> >> On my test machine, the first one runs about 6.3 seconds and the second one >> about 0.13 seconds. >> >> -Mike >> >>> From: Ricardo Tomasi >>> >>> Concatenating into a string is already much faster than >>> appending in each loop, there is not much room for >>> improvement left. What you can do improve user experience >>> though is split that into a recursive function over a >>> setTimeout, so that the browser doesn't freeze and you can >>> display a nice loading animation. >>> >>> >>> On Feb 5, 5:03 pm, James <james.gp....@gmail.com> wrote: >>> > I need tips on optimizing a large DOM insert to lessen the >>> "freeze" on >>> > the browser. >>> > >>> > Scenario: >>> > I receive a large amount of JSON 'data' through AJAX from a >>> database >>> > (sorted the way I want viewed), and loop through them to >>> add to a JS >>> > string, and insert that chunk of string into a tbody of a >>> table. Then, >>> > I run a plug-in that formats the table (with pagination, etc.). >>> > Simplified sample code: >>> > >>> > var html = ''; >>> > $.each(data, function(i, row) { >>> > html += '<tr><td>data from json</td></tr>';}); >>> > >>> > $("tbody").append(html); >>> > $("table").formatTable(); >>> > >>> > formatTable() requires that the table has to be "completed" >>> before it >>> > can be executed. >>> > Is there any way I can optimize this better? I think I've read >>> > somewhere that making a string too long is not good, but I've also >>> > read that updating the DOM on each iteration is even worst. >>> > >>> > Any advice would be appreciated! >>> >> >> >
