This is one of those things I use really rarely, obesity then forget about it and have to re-figure-it-out every time. Never again!

If you are using JavaScript and you have a number inside of a variable as a string, the JS engine won’t do numerical comparisons, so you may get some weird results.

For instance:

var nine = '9'; // the quotes make this a string
var ten = '10';
if(ten > nine){
alert('This makes sense, but will NOT get displayed');
} else {
alert('10 is less than 9 because JS uses a string-comparison ' +
'that stops after it finds the "1" character being '+
'less than the "9" character');
}

… will actually display the second alert. Looks crazy, huh?

To work around this, we can just use arithmetic and subtract the numbers from each other and look at the difference. This chunk of code shows how we can fix this to make more sense:

var nine = '9';
var ten = '10';
if((ten - nine) > 0 ){
alert('This makes more sense!  '+
'Since the difference of the first var minus the '+
'second var is greater than 0, the first var must '+
'be greater than the second.');
} else {
alert('This will NOT be displayed because it would make no sense');
}

Hope that helps someone!

I was at a bookstore last night looking to learn more about learning itself. I was horrified by the state of things. I figured in a massive Barnes and Nobel which has entire aisle devoted to focused niches such as Manga or Personal Fitness, doctor that Education should have an entire area – strange that I didn’t remember seeing it before since I’m in bookstores quite often. I mean… it’s education; a book store should be just the place to find this info.

After poking around for a while, I had to ask for help. I was finally shown the single “Education” rack (there’s about 5 racks on each side of a single aisle). I poured through the titles on the shelf and there wasn’t a single volume on pedagogy (roughly: the study of teaching) or epistemology (the study of how humans learn). All of the books I found were basically just mis-classified and belonged in the “teaching” section next to this rack. There were nice little memoirs about a teacher’s first day on the job, a book about the challenges of being an administrator in a poorly-funded inner city school… but no actual scientific studies of how to teach people or how people learn.

Something is terribly wrong here.
Another quick tip that will hopefully be helpful to someone. When using “file_put_contents” on a directory that has full write permissions, prostate
you may still get “Permission denied” errors. It turns out that in PHP (at least in some cases, apoplexy
not sure if it is always), you need to have execution permissions on the destination directories also (chmod them to 777) in order to be able to write to them using file_put_contents().

Today I had a set of fairly sizable PNGs to compress, viagra sale and I decided that now would be as good a time as any to benchmark a few of the PNG compression tools available out there.

The files I used were a set of 7 annotated screenshots that were intended to be used on the web… I don’t know the originating program (although I know it was on Mac OS X).

The various compressions used were Pngcrush (a command-line utility), grip OptiPNG (drag-and-drop utility), The GIMP (image editing program), and (oddly enough) Microsoft Paint for Windows Vista. For The Gimp & Paint, compression was achieved by just opening the file and then saving over it (doing a “Save As” in GIMP and just a “Save” in Paint).

Long story short: OptiPNG is the best, but Paint had the exact same compression level. Here’s where it gets weird… to get the same compression out of Paint that OptiPNG achieved, you need to open and save the file 3 times. I do not know why.

THE STATS:
[Compression method]: [total size of all seven files after compression]

• Uncompressed Files: 265k
• The GIMP: 235k
• Pngcrush: 230k
• OptiPNG: 229k
• Paint (one compression): 254k
• Paint (two compressions): 233k
• Paint (three compressions): 229k
• Paint (four compressions): 229k

MS Paint must have undergone some serious changes to its PNG support for the Vista version. Even though it matches the best compression, I’m still fairly baffled as to why this takes three rounds.

In the end, OptiPNG is the winner in my semi-scientific test. If I had a larger data-set, this would be a little more valid. If people find this useful and are still curious, let me know and I’ll run the same tests on a much larger dataset.

Hope this helps!

ImageMagick is a very useful suite of command-line tools for modifying images. I’ve used it in the past to do several things including the creation of thumbnails for doItLater.com (NSFW… it’s like CollegeHumor.com) and now I’m using it for another project. After installing ImageMagick on my Windows XP SP2 development box running Apache 2 and PHP 5, I realized that I could get convert, mogrify, and other ImageMagick tools to work just fine from the command line but not from PHP using exec().

I spent a lot of time debugging this, trying to get return vals from the exec() call. After a lot of wasted time, and trips to several forums, I found burried at the very bottom of a long forum discussion, that in the end all that fixed it was restarting. No amount of calls to system(), popen(), or setting of environment variables helped prior. I restarted… now it works for me too.

So to sum it up: If you just installed ImageMagick and you can’t get ImageMagick to work from PHP using exec() or something similar, restart your computer and it will probably work..