CODEWITHSUNDEEP
jquery
LaBombeta
LaBombeta

Reputation: 45

jQuery: I dont understand what "i" is in .each(function(i)

I'm trying to understand this jquery code, I understand all of it: the modulo, loop etc., except for what "i" means in .each(function(i). I've tried searching but this code doesn't return good search results. Does it represent each img that has an id of #photos? If so isn't that the same as the variable currentPhoto. Any help with understanding this or a link to useful info would be greatly appreciated.

function rotatePics(currentPhoto) {  //number is index of current photo
  var numberOfPhotos = $('#photos img').length;
  currentPhoto = currentPhoto % numberOfPhotos;

  $('#photos img').eq(currentPhoto).fadeOut(function() {
    // re-order the z-index
$('#photos img').each(function(i) {
  $(this).css(
    'zIndex', ((numberOfPhotos - i) + currentPhoto) % numberOfPhotos
  );
});
$(this).show();
setTimeout(function() {rotatePics(++currentPhoto);}, 4000);
  });
}

Thanks in advance!

Edit: In case anyone going through the jquery: novice to ninja book has the same doubts: (i) is 0 based and currentPhoto is 1 based, so for example the 1st img element would look like this(assuming there are 6 photos total):

((6        -       0) +      1        %     6
((numberOfPhotos - i) + currentPhoto) % numberOfPhotos

always adding 1 makes sure the remainder is always 1, thus making sure that the z-index is always 1.

Thanks for everybodies help!

Upvotes: 4

Views: 225

Answers (4)

Yekmer Simsek
Yekmer Simsek

Reputation: 4102

each() function is documented here http://api.jquery.com/each/

By using jquery selectors you will have a list of objects, and i will be the index of these elements in dom creation order.

Upvotes: 4

ChrisThompson
ChrisThompson

Reputation: 2008

'i' should represent the index within the loop.

Upvotes: 3

herostwist
herostwist

Reputation: 3968

i is the index position of the current element within the jquery collection

Upvotes: 7

Kon
Kon

Reputation: 27441

The definition might help.

Upvotes: 5

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