JavaScript: Can some explane what this code is doing... [Resolved]

[Misspell]

Can somone explane to me how this code works.

:snip:

var parts = {front:1<<0, back:1<<1, cd:1<<2, cd2:1<<3, cd3:1<<4, cd4:1<<5, inside:1<<6, inlay:1<<7};

	var titleCode = elem.options[elem.selectedIndex].value;

	for (var i in parts) {
		if(titleCode&parts[i]) {
			//alert(titleCode + " <>" + i);
			buffer += '[<a href="" onClick="titlePart.value=\''+i+'\';titleSubmit.focus();return false;" '; // set part to property name
			buffer += 'onMouseOver="window.status=\''+ucFirst(i)+'\';return true;" onMouseOut="window.status=\'\';return true;">';
			buffer += '<strong>'+ucFirst(i)+'</strong></a>]&nbsp;&nbsp;';
		}
	}

:/snip:


I know what the out come is and where the info is coming from, but dont know how it does its thing.
Heres an example of what it does:

elem.options[elem.selectedIndex].value is 197 (taking from a <select> box off a form)

when looping through the 'parts' array (???) it will turn that 197 into;
[Front] [Cd] [Inside] [Inlay] (takin from the 'parts' array)

The ucFirst() function just capitalize the first letter of the values held in the 'parts' array.

If elem.options[elem.selectedIndex].value = 1 then it would return;
[Front]
If elem.options[elem.selectedIndex].value = 5 it would return;
[Front] [Cd]

Theres all different values for elem.options[elem.selectedIndex].value which display different combinations of the 'part' array.

And what does the #<<# in the 'parts' array mean/do ?

As you can see, I dont know too much about Javascript.
The attach file is the javascript and a clip of the forum that calls the script (so you can see it in action).

Heres what im doing (if you care ).
I have a VB program ive made for myself and a friend.
With-in this program i 'Inet' a url and then i phase through the HTML source and pull out the info we want, then display that info in a listview. Noramly part of that info would work with the javascript, but im converting that to function under VB. Im not looking for the "javascript => VB" code here, i would just like to know excatly how the code above translates the numbers into the words and what the #<<# does.


Hope that made sense, thanks for any help.

[Misspell]

Posted this questions on another board and heres the responce that helped.

And what does the #<<# in the 'parts' array mean/do ?

x << y is binary left shift (shift x, y times to the left)

as result:
parts.front == 1
...
...
...
parts.inlay == 128

here it is as 2^n (2^0 == 1, 2^7 == 128)

Since i was not familur with Binary, this link helped:
http://www.devarticles.com/c/a/JavaS...ors-continued/


So for my VB app i just convered the 'titleCode' ID to binary, held the 'parts' variable in an array and looped Mid(ByteToBin(titleCode_ID), x, 1) (looped to see what was "on/1" and "off/0") then compaired the 1's and 0's to my array.

Thouhgt i would post it here incase somone else was wondering.


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