addEventListener复杂一点点

包含了自执行函数的概念

by kixi

HTML

<div id='aaa'>
    <p id='cccc' style="background:#c00;">点击</p>
</div>
<div id="bbb" style=" background:blue;">1</div>

CSS

/*
清晰网
kixi.com.cn
从javascript开始
*/

JavaScript

var addEvent = (function () {
    if (document.addEventListener) {
        return function (el, type, fn) {
            if (el.length) {
                for (var i = 0; i < el.length; i++) {
                    addEvent(el[i], type, fn);
                }
            } else {
                el.addEventListener(type, fn, false);
            }
        };
    } else {
        return function (el, type, fn) {
            if (el.length) {
                for (var i = 0; i < el.length; i++) {
                    addEvent(el[i], type, fn);
                }
            } else {
                el.attachEvent('on' + type, function () {
                    return fn.call(el, window.event);
                });
            }
        };
    }
})();

function valert(){
    alert('清晰网，从javascript开始！');
}

var ccc = document.getElementById('cccc');
addEvent(ccc,'click',valert);