优化javascript代码[重复]

Question

Can anybody help me to optimize this javascript code? I see repeat. May I avoid this repeat?

Thanks!

var billboardTimer;
var billboardCurrent = 0;
var billboardSize = $('.billboard li').size();
$('.billboard li').on('click', function(){
    clearInterval(billboardTimer);
    $('.billboard li').removeClass('active');
    $(this).addClass('active');
    $('.billboard .img-large').removeClass('current').removeAttr('style');
    $('.billboard .img-large').eq($(this).index()).animate({'opacity': 1}).show();
});
$('.billboard li:first').click();
billboardTimer = setInterval(billboardNext, 2000);
function billboardNext(){
    billboardCurrent++;
    if (billboardCurrent == billboardSize) {billboardCurrent = 0;}
    $('.billboard .img-large').removeClass('current').removeAttr('style');
    $('.billboard .img-large').eq(billboardCurrent).animate({'opacity': 1}).show();
    $('.billboard li').removeClass('active');
    $('.billboard li').eq(billboardCurrent).addClass('active');
}

Link jsfiddle.net

Answer 1

Perhaps something like this?

var billboardTimer;
var billboardCurrent = 0;
var billboardSize = $('.billboard li').size();

$('.billboard li').on('click', function(){
    clearInterval(billboardTimer);
    setActive($(this).index());
});
$('.billboard li:first').click();
billboardTimer = setInterval(function() {
    setActive(billboardCurrent = (billboardCurrent + 1) % billboardSize);
}, 2000)
function setActive(index) {
    $('.billboard .current').animate({'opacity': 0}).removeClass('current');;
    $('.billboard .img-large').eq(index).animate({ 'opacity': 1}).addClass('current');
    $('.billboard li').removeClass('active').eq(index).addClass('active');
}

http://jsfiddle.net/9dxcc/2/