JS 常用方法合集

部分方法使用jQuery！！！
//tab切换
/*
*   参数tablist为触发事件id
*   参数tabmain为执行切换id
*   参数ev为触发事件的动作
*/
function tab(tablist,tabmain,ev){
    $(tablist).bind(ev,function(){
        var mythis= this;
        var n= $(this).index();
        $($(this).siblings()).removeClass("active");
        $(this).addClass("active");
        $(tabmain).removeClass("active");
        $($(tabmain)[n]).addClass("active");
    });
}

//重写移动端触屏点击（无延迟）
$.fn.ontouch = function(callback,bool){
    var _x,_y,_s,
        _t = {
            s : function(event){
                var t = getTouch(event);
                _x = t.clientX;
                _y = t.clientY;
                _s = true;
            },
            m : function(event){
                if(_s){
                    var t = getTouch(event);
                    if(_x != t.clientX || _y != t.clientY){
                        _s = false;
                    }
                }
            },
            e : function(event){
                if(_s){
                    callback.call(this);
                    if(bool){
                        event.preventDefault();
                        return false;
                    }
                }
            }
        };

    function getTouch(event){
        return event.originalEvent.touches[0] ? event.originalEvent.touches[0] : event;
    };

    this.bind({
        "touchstart" : _t.s,
        "touchmove" : _t.m,
        "touchend" : _t.e
    });
    return this;
};

/*验证手机号码*/
function isTelNum(str){
    var _tel = $.trim(str),
        _reg = /^0?1[3|4|5|6|7|8|9][0-9]\d{8}$/;
    return _reg.test(_tel);
};

/*验证邮件地址*/
function isEmail (value, target) {
     value = value.trim();
     if (!/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(value)) {
         target.val("");
        return true;
     }
 }

//匹配国内电话号码(0511-4405222 或 021-87888822)   
function istell(str) {  
    var result = str.match(/\d{3}-\d{8}|\d{4}-\d{7}/);  
    if (result == null) return false;  
    return true;  
}  

//匹配身份证(15位或18位)   
function isidcard(str) {  
    var result = str.match(/\d{15}|\d{18}/);  
    if (result == null) return false;  
    return true;  
}  

//判断是否移动设备访问  
function isMobileUserAgent() {  
    return (/iphone|ipod|android.*mobile|windows.*phone|blackberry.*mobile/i.test(window.navigator.userAgent.toLowerCase()));  
}  

//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;  
    }  
}  

/*
*移动端简单监听滑动方向方法
*/
// 返回角度
function GetSlideAngle(dx, dy) {
    return Math.atan2(dy, dx) * 180 / Math.PI;
}

//根据起点和终点返回方向 1：向上，2：向下，3：向左，4：向右,0：未滑动
function GetSlideDirection(startX, startY, endX, endY) {
    var dy = startY - endY;
    var dx = endX - startX;
    var result = 0;

    //如果滑动距离太短
    if(Math.abs(dx) < 50 && Math.abs(dy) <50) {
        return result;
    }

    var angle = GetSlideAngle(dx, dy);
    if(angle >= -45 && angle < 45) {
        result = 4;
    }else if (angle >= 45 && angle < 135) {
        result = 1;
    }else if (angle >= -135 && angle < -45) {
        result = 2;
    }
    else if ((angle >= 135 && angle <= 180) || (angle >= -180 && angle < -135)) {
        result = 3;
    }

    return result;
}

function touchMove() {
    //滑动处理
    var startX, startY;
    var a = document.getElementById("room_img")? document.getElementById("room_img"):document;
    a.addEventListener('touchstart',function (ev) {
        startX = ev.touches[0].pageX;
        startY = ev.touches[0].pageY;
    }, false);
    a.addEventListener('touchend',function (ev) {
        var endX, endY;
        endX = ev.changedTouches[0].pageX;
        endY = ev.changedTouches[0].pageY;
        var direction = GetSlideDirection(startX, startY, endX, endY);
        switch(direction) {
            case 0:
                // alert("没滑动");
                break;
            case 1:
                console.log("向上");
                break;
            case 2:
                console.log("向下");
                break;
            case 3:
                console.log("向左");
                break;
            case 4:
                console.log("向右");
                break;
            default:
        }
    }, false);
}

/*正则替换text/plain*/
$.replace = function(temp, data, regexp){
    if(!(Object.prototype.toString.call(data) === "[object Array]")) data = [data];
    var ret = [];
    for(var i=0,j=data.length;i<j;i++){
        ret.push(replaceAction(data[i]));
    }
    return ret.join("");
    function replaceAction(object){
        return temp.replace(regexp || (/\\?\{([^}]+)\}/g), function(match, name){
            if (match.charAt(0) == '\\') return match.slice(1);
            return (object[name] != undefined) ? object[name] : '';
        });
    }
};

/*简单使用案例
<html>
<script type="text/plain" id="testDemo">
    <div>{a}</div>
    <span>{b}<span>
</script>
<script type="text/javascript">
    var data = {"a":"a","b":"b"};
    var html = replace("testDemo",data);
    $("html").append(html);
</script>
</html>
*/

/*获取url参数*/
function GetQueryString(name)
{
    var reg = new RegExp("(^|&)"+ name +"=([^&]*)(&|$)");
    var r = window.location.search.substr(1).match(reg);
    if(r!=null)return  unescape(r[2]); return null;
}

/*输入框焦点获取和失去时显示默认文字*/
function input_focus (inputId) {
   $(inputId).bind({
        focus:function(){
            if (this.value == this.defaultValue){
                this.value="";
            }
        },
        blur:function(){
            if (this.value == ""){
                this.value = this.defaultValue;
            }
        }
    });
}

/*阻止事件冒泡*/
function stopEvent(event){ 
    //取消事件冒泡
    var e=arguments.callee.caller.arguments[0]||event; //若省略此句，下面的e改为event，IE运行可以，但是其他浏览器就不兼容
    if (e && e.stopPropagation) {
        // this code is for Mozilla and Opera
        e.stopPropagation();
    } else if (window.event) {
        // this code is for IE
        window.event.cancelBubble = true;
    }
}

//写cookies
function setCookie(c_name,value,expiredays)
{
    var exdate=new Date();
    exdate.setDate(exdate.getDate()+expiredays);
    document.cookie=c_name+ "=" +escape(value)+
        ((expiredays==null) ? "" : ";expires="+exdate.toGMTString())
}

//读cookie
function getCookie(c_name)
{
    if (document.cookie.length>0)
    {
        c_start=document.cookie.indexOf(c_name + "=");
        if (c_start!=-1)
        {
            c_start=c_start + c_name.length+1;
            c_end=document.cookie.indexOf(";",c_start);
            if (c_end==-1) c_end=document.cookie.length;
            return unescape(document.cookie.substring(c_start,c_end))
        }
    }
    return ""
}

/*仿原生app滑动切换*/

//html结构
//  <div class="focus_map" id="tabs">
//     <div class="border">
//         <ul class="atlas">
//         </ul>
//     </div>
// </div>

//css样式
// .focus_map { height: 3.2rem; position: relative; overflow: hidden; }
// .focus_map .border { height: 100%; width: 100%; overflow: hidden; }
// .focus_map ul { width: 200rem; height: 100%; }
// .focus_map li { width: 7.5rem; height: 100%; overflow: hidden; -webkit-overflow-scrolling: touch; }
// .focus_map img { width: 100%; vertical-align: middle; }
// .focus_map nav { position: absolute; left: 0; bottom: .15rem; width: 100%; text-align: center; }
// .focus_map nav i { display: inline-block; margin: 0 .1rem; border-radius: 50%; width: .16rem; height: .16rem; border-radius: .25rem; background: #bbbbbb; }
// .focus_map nav i.cur { background: #1f80b8; }

function focusbind(){

    //对象&变量 缓存
    var $tab = $("#tabs"),
        $ul = $tab.find("ul"),
        $li = $ul.children(),
        $nav = $("<nav>"),
        li_len = $li.length,
        li_w = $li.eq(0).width();

    //容器 初始化
    $li.css({
        "float" : "left",
        "width" : li_w
    })
        .each(function(i){
            var str = i == 0 ? "<i class=\"cur\">" : "<i>";
            $nav.append(str);
        });
    $nav.appendTo($tab);
    $li.eq(0).clone().appendTo($ul);
    $li.eq(-1).clone().css("marginLeft",-li_w).prependTo($ul);
    $ul.css("float","left").width(li_w * $ul.children().length);

    //切换 方法
    var eventOff,startX,clientX,
        index = 0,
        eventMaxWidth = li_w,
        objStatus = {},
        eventTo,
        time=5000,
        tab = {
            //开始
            start : function (event){
                //重置水平位置
                clientX = 0;
                //滑动激活
                eventOff = true;
                //获取鼠标||触点水平坐标
                var touch = event.touches && event.touches[0] || event;
                //记录初始坐标
                startX = touch.clientX;
                //记录切换前对象状态
                objStatus.left = $ul.get(0).style.marginLeft;
                //阻止对象默认行为
                // event.preventDefault();
                console.log("准备切换");
                clearInterval(eventTo);
            },
            //移动
            move : function (event){
                var touch = event.touches && event.touches[0] || event,
                    _x = touch.clientX - startX;
                if(eventOff){
                    clientX = parseInt(_x/eventMaxWidth * 100);
                    $ul.get(0).style.marginLeft = (li_w * clientX / 100) - li_w * index + "px";
                    //console.log("滑动进度：" + clientX + "%");
                }
                event.preventDefault();
            },
            //结束
            end : function (event){
                var _clientX = clientX > 0 ? clientX : -(clientX);
                //滑动激活，且滑动百分比超过50
                if(eventOff){
                    if(_clientX >= 30){
                        index = clientX > 0 ? index - 1 : index + 1;
                        tab.to();
                        console.log("切换完成");
                    }
                    else{
                        console.log("放弃切换");

                        $ul.animate({
                            "marginLeft" : objStatus.left
                        });
                    }

                    eventOff = false;
                }
                eventTo = setInterval(function(){
                    index++;
                    tab.to();
                },time);
                // event.preventDefault();
            },
            to:function(){
                var moveCallback;
                objStatus.left = -(li_w * index) + "px";
                //复位
                if(index >= li_len){
                    index = 0;
                    moveCallback = function(){
                        $ul.get(0).style.marginLeft = -(li_w * index) + "px";
                    };
                }
                else if(index < 0){
                    index = li_len - 1;
                    moveCallback = function(){
                        $ul.get(0).style.marginLeft = -(li_w * index) + "px";
                    };
                }
                $nav.children().eq(index).addClass("cur").siblings().removeClass("cur");
                $ul.animate({
                    "marginLeft" : objStatus.left
                },moveCallback);
            }
        };

    eventTo = setInterval(function(){
        index++;
        tab.to();
    },time);

    //触摸事件 注册
    $tab.get(0).addEventListener("touchstart",tab.start,false);
    $tab.get(0).addEventListener("touchmove",tab.move,false);
    $tab.get(0).addEventListener("touchend",tab.end,false);
}

/*原生js获取class*/
function getElementByClassName(classnames){   
    var objArray= new Array();//定义返回对象数组  
    var tags=document.getElementsByTagName("*");//获取页面所有元素  
    var index = 0;  
    for(var i in tags){  
        if(tags[i].nodeType==1){  
            if(tags[i].getAttribute("class") == classnames){ //如果某元素的class值为所需要  
                objArray[index]=tags[i];  
                index++;  
            }   
        }   
    }   
    return objArray;  
} 

//获取鼠标的位置。兼容ie678
function getXY(e){
    var ev = e || window.event;
    var x=0,y=0;
    if(ev.pageX){
        x = ev.pageX;
        y = ev.pageY;
    }else{
        //拿到scrollTop 和scrollLeft
        var sleft = 0,stop = 0;
        //ie678---
        if(document.documentElement){
            stop =document.documentElement.scrollTop;
            sleft = document.documentElement.scrollLeft;
        }else{
        //ie9+ 谷歌 
            stop = document.body.scrollTop;
            sleft = document.body.scrollLeft;
        }   
        x = ev.clientX + sleft;
        y = ev.clientY + stop;
    }
    return {x:x,y:y};
};

//范围随机数
function randomRange(start,end){
    return Math.floor(Math.random()*(end-start+1))+start;
};

//随机颜色
function randomColor(){
    var r = Math.floor(Math.random()*256);
    var g = Math.floor(Math.random()*256);
    var b = Math.floor(Math.random()*256);
    return "rgb("+r+","+g+","+b+")";//IE7不支出rgb
};

/*是否为微信浏览器*/
function isWeiXin(){ 
    var ua = window.navigator.userAgent.toLowerCase(); 
    if(ua.match(/MicroMessenger/i) == 'micromessenger'){ 
        return true; 
    }else{ 
        return false; 
    } 
} 

/*Jq获取屏幕各种高度*/
$(document).ready(function(){
alert($(window).height()); //浏览器当前窗口可视区域高度
alert($(document).height()); //浏览器当前窗口文档的高度
alert($(document.body).height());//浏览器当前窗口文档body的高度
alert($(document.body).outerHeight(true));//浏览器当前窗口文档body的总高度 包括border padding margin
alert($(window).width()); //浏览器当前窗口可视区域宽度
alert($(document).width());//浏览器当前窗口文档对象宽度
alert($(document.body).width());//浏览器当前窗口文档body的宽度
alert($(document.body).outerWidth(true));//浏览器当前窗口文档body的总宽度 包括border padding margin

})

/*固定时间的倒计时*/
function countdown(){
    var endtime = newDate("Jan 18, 2015 23:50:00");
    var nowtime = newDate();
    if (nowtime >= endtime) {
        document.getElementById("_lefttime").innerHTML = "倒计时间结束";
        return;
    }

    var leftsecond = parseInt((endtime.getTime() - nowtime.getTime()) / 1000);
    if (leftsecond < 0) {
        leftsecond = 0;
    }

    __d = parseInt(leftsecond / 3600 / 24);
    __h = parseInt((leftsecond / 3600) % 24);
    __m = parseInt((leftsecond / 60) % 60); 
    __s = parseInt(leftsecond % 60);
    document.getElementById("_lefttime").innerHTML = __d + "天" + __h + "小时" + __m + "分" + __s + "秒";
}

countdown();
setInterval(countdown, 1000);

/*控制浏览器进入全屏模式*/
function fullScreen() {
    var el = document.documentElement,
        rfs = el.requestFullScreen || el.webkitRequestFullScreen || el.mozRequestFullScreen || el.msRequestFullScreen,
        wscript;

    if(typeof rfs != "undefined" && rfs) {
        rfs.call(el);
        return;
    }

    if(typeof window.ActiveXObject != "undefined") {
        wscript = new ActiveXObject("WScript.Shell");
        if(wscript) {
            wscript.SendKeys("{F11}");
        }
    }
}

 /*退出全屏模式*/
function exitFullScreen() {
    var el = document,
        cfs = el.cancelFullScreen || el.webkitCancelFullScreen || el.mozCancelFullScreen || el.exitFullScreen,
        wscript;

    if (typeof cfs != "undefined" && cfs) {
      cfs.call(el);
      return;
    }

    if (typeof window.ActiveXObject != "undefined") {
        wscript = new ActiveXObject("WScript.Shell");
        if (wscript != null) {
            wscript.SendKeys("{F11}");
        }
    }
}

/*字符串超出省略 */

String.prototype.cutstr = function (len) {  
    var restr = this;  
    var wlength = this.replace(/[^\x00-\xff]/g, "**").length;  
    if (wlength > len) {  
        for (var k = len / 2; k < this.length; k++) {  
            if (this.substr(0, k).replace(/[^\x00-\xff]/g, "**").length >= len) {  
                restr = this.substr(0, k) + "...";  
                break;  
            }  
        }  
    }  
    return restr;  
}  

// 返回字符串的实际长度, 一个汉字算2个长度   
String.prototype.strlen = function () {  
    return this.replace(/[^\x00-\xff]/g, "**").length;  
}  

//转义html标签  
function HtmlEncode(text) {  
    return text.replace(/&/g, '&').replace(/\"/g, '"').replace(/</g, '<').replace(/>/g, '>')  
}  

作者：ydx425
链接：http://www.imooc.com/article/16942
来源：慕课网
本文原创发布于慕课网。