Although you may think it’s gibberish, the text above is the regular expression I’m using for the solution to my earlier problem. Doesn’t look very "regular" does it? Aside from the fact it’s using characters I’m familiar with, the order and meaning behind them might as well be hieroglyphics to me. So, what is a "regular expression"?

The Wiktionary website defines it as follows:

A concise description of a regular formal language with notations for concatenation, alternation, and iteration (repetition) of subexpressions.

My task for my application was to exclude any .zip files from being able to be uploaded to the server. I couldn’t ever find a regular expression that excluded .zip files, but I did find the one above that basically allowed a list of other files.

Here’s the expression above again:

^.+\.(([jJ][pP][eE]?[gG])|([gG][iI][fF])|([pP][dD][fF])|([dD][oO][cC])|([dD][oO][cC][xX])|([bB][mM][pP])|([tT][xX][tT]))$

The "regular expression", or "regex" above basically looks for any .jpg, .jpeg, .gif, .pdf, .bmp, .doc, .docx, or .txt file and allows it to be uploaded. The upper and lower case version of the letter within brackets specifies that the file extension could be typed either way.

I’m still not real sure what all the other symbols are really specifying in there. I’ve got more to learn for sure.

Post from: EveryJoe

The program is a high-tech etch-a-sketch. You can draw on the iPhone using your fingers and then shake the device to erase it.

He’s fluent in a number of programming language. At the age of 9 I could barely cope with the english language, much less programming languages. He’s the man!

Read the original article from Reuters here.

Post from: EveryJoe