分享原生JavaScript技巧大收集(41~50)

文章来源：jquery教程 - http://www.jq-school.com/Show.aspx?id=304

41、原生JavaScript完美判断是否为网址

function IsURL(strUrl) {    var regular = /^\b(((https?|ftp):\/\/)?[-a-z0-9]+(\.[-a-z0-9]+)*\.(?:com|edu|gov|int|mil|net|org|biz|info|name|museum|asia|coop|aero|[a-z][a-z]|((25[0-5])|(2[0-4]\d)|(1\d\d)|([1-9]\d)|\d))\b(\/[-a-z0-9_:\@&?=+,.!\/~%\$]*)?)$/i    if (regular.test(strUrl)) {        return true;    }    else {        return false;    }}

42、原生JavaScript根据样式名称检索元素对象

function getElementsByClassName(name) {    var tags = document.getElementsByTagName('*') || document.all;    var els = [];    for (var i = 0; i < tags.length; i++) {        if (tags[i].className) {            var cs = tags[i].className.split(' ');            for (var j = 0; j < cs.length; j++) {                if (name == cs[j]) {                    els.push(tags[i]);                    break                }            }        }    }    return els}

43、原生JavaScript判断是否以某个字符串开头

String.prototype.startWith = function (s) {    return this.indexOf(s) == 0}

44、原生JavaScript判断是否以某个字符串结束

String.prototype.endWith = function (s) {    var d = this.length - s.length;    return (d >= 0 && this.lastIndexOf(s) == d)}

45、原生JavaScript返回IE浏览器的版本号

function getIE(){    if (window.ActiveXObject){        var v = navigator.userAgent.match(/MSIE ([^;]+)/)[1];        return parseFloat(v.substring(0, v.indexOf(".")))    }    return false}

46、原生JavaScript获取页面高度

function getPageHeight(){var g = document, a = g.body, f = g.documentElement, d = g.compatMode == "BackCompat"? a: g.documentElement;return Math.max(f.scrollHeight, a.scrollHeight, d.clientHeight);}

47、原生JavaScript获取页面scrollLeft

function getPageScrollLeft(){var a = document;return a.documentElement.scrollLeft || a.body.scrollLeft;}

48、原生JavaScript获取页面可视宽度

function getPageViewWidth(){var d = document, a = d.compatMode == "BackCompat"? d.body: d.documentElement;return a.clientWidth;}

49、原生JavaScript获取页面宽度

function getPageWidth(){var g = document, a = g.body, f = g.documentElement, d = g.compatMode == "BackCompat"? a: g.documentElement;return Math.max(f.scrollWidth, a.scrollWidth, d.clientWidth);}

50、原生JavaScript获取页面scrollTop

function getPageScrollTop(){var a = document;return a.documentElement.scrollTop || a.body.scrollTop;}