原生javascript实现图片轮播效果代码_javascript技巧

function id(name) {return document.getElementById(name);}
//遍历函数
function each(arr, callback) {
if (arr.forEach) {arr.forEach(callback);}
else {
for (var i = 0, len = arr.length; i }
function fadeIn(elem) {
setOpacity(elem, 0)
for ( var i = 0; i (function() {
var pos = i * 5;
setTimeout(function() {
setOpacity(elem, pos)
}, i * 25);
})(i);
}
}
function fadeOut(elem) {
for ( var i = 0; i (function() {
var pos = 100 - i * 5;
setTimeout(function() {
setOpacity(elem, pos)
}, i * 25);
})(i);
}
}
// 设置透明度
function setOpacity(elem, level) {
if (elem.filters) {
elem.style.filter = "alpha(opacity=" + level + ")";
} else {
elem.style.opacity = level / 100;
}
}