文章标题

1:判断字符串和对象和数组是否为空:

var hasOwnProperty = Object.prototype.hasOwnProperty;//判断一个数组,对象,字符串是否为空function isEmpty(obj) {    // 本身为空直接返回true    if (obj == null) return true;    // 然后可以根据长度判断，在低版本的ie浏览器中无法这样判断。    if (obj.length > 0)    return false;    if (obj.length === 0)  return true;    //最后通过属性长度判断。    for (var key in obj) {        if (hasOwnProperty.call(obj, key)) return false;    }    return true;}

2:下载文件:

window.downloadFile = function (sUrl) {    //iOS devices do not support downloading. We have to inform user about this.    if (/(iP)/g.test(navigator.userAgent)) {        alert('Your device does not support files downloading. Please try again in desktop browser.');        return false;    }    //If in Chrome or Safari - download via virtual link click    if (window.downloadFile.isChrome || window.downloadFile.isSafari) {        //Creating new link node.        var link = document.createElement('a');        link.href = sUrl;        if (link.download !== undefined) {            //Set HTML5 download attribute. This will prevent file from opening if supported.            var fileName = sUrl.substring(sUrl.lastIndexOf('/') + 1, sUrl.length);            link.download = fileName;        }        //Dispatching click event.        if (document.createEvent) {            var e = document.createEvent('MouseEvents');            e.initEvent('click', true, true);            link.dispatchEvent(e);            return true;        }    }    // Force file download (whether supported by server).    if (sUrl.indexOf('?') === -1) {        sUrl += '?download';    }    window.open(sUrl, '_self');    return true;}window.downloadFile.isChrome = navigator.userAgent.toLowerCase().indexOf('chrome') > -1;window.downloadFile.isSafari = navigator.userAgent.toLowerCase().indexOf('safari') > -1;调用方法:window.downloadFile(url)

3:返回url对象

//返回url参数对象function zs_getUrlParamObj() {    var name, value, str, num, arr;    var retObj = {};    str = location.href.substr(location.href.indexOf("?") + 1);    arr = str.split("&"); //各个参数放到数组里    for (var i = 0; i < arr.length; i++) {        num = arr[i].indexOf("=");        if (num > 0) {            name = arr[i].substring(0, num);            value = arr[i].substr(num + 1);            retObj[name] = value;        }    }    return retObj;}用法:eg: "a.html"+"?deviceId="+deviceid + "&loopName=" + loopName;页面中用 var urlCanshu = zs_getUrlParamObj();urlCanshu.deviceIdurlCanshu.loopName

4:判断数组是否重复

function arrDouble(a, b) {    /*a是一个数组     b:分割字符；     */    var isT = false;    for (var len = 0; len < a.length; len++) {        if (b == a[len]) {            isT = true;            break;        }    }    ;    return isT}用法:eg: var gg = arrDouble(isDouble,indexName); if(gg){    layer.msg("该指标项已经存在！", {time : 1000, icon : 2});}

5:字符串截取

function stringSplit(a, b, c) {    /*a:分割对象； a是一个数组     b:分割字符；     c:分割后取值的下标     */    var strs = new Array(), //定义一数组        arr = new Array(),        code = '';//分割后的字符输出    for (var len = 0; len < a.length; len++) {        strs = a[len].split(b); //字符分割        arr.push(strs[c]);        if (len == 0) {            code += arr[0];        } else {            code += ',' + arr[len];        }        ;    }    ;    return code;}用法:eg:var str = ['ECEP_EQUIP_TYPE_VALUE_index00','ECEP_EQUIP_TYPE_VALUE_index01','ECEP_EQUIP_TYPE_VALUE_index02','ECEP_EQUIP_TYPE_VALUE_index03'];var code1 = stringSplit(str,"ECEP_EQUIP_TYPE_VALUE_",1)console.log(code1);"index00,index01,index02,index03"

6:删除数组元素

//根据数组下标删除数组中某个元素Array.prototype.del = function (index) {    if (isNaN(index) || index >= this.length) {        return false;    }    for (var i = 0, n = 0; i < this.length; i++) {        if (this[i] != this[index]) {            this[n++] = this[i];        }    }    this.length -= 1;};//删除数组某个元素(根据value值)Array.prototype.indexOf = function (val) {    for (var i = 0; i < this.length; i++) {        if (this[i] == val) return i;    }    return -1;};Array.prototype.remove = function (val) {    var index = this.indexOf(val);    if (index > -1) {        this.splice(index, 1);    }};

7:tab切换

function TabChange() {};TabChange.prototype = {    on: function (tabs, divs, liClaON, liclass) {        var _this = this;        if (tabs.length != divs.length) {            alert("菜单层数量和内容区数量不一致！");            return false;        }        for (var i = 0; i < tabs.length; i++) {            _this.$(tabs[i]).value = i;            _this.$(tabs[i]).onclick = function () {                for (var j = 0; j < tabs.length; j++) {                    _this.$(divs[j]).style.display = "none";                    _this.$(tabs[j]).className = '' + liclass;                }                _this.$(tabs[this.value]).className = '' + liClaON;                _this.$(divs[this.value]).style.display = "block";            }        }    },    $: function (oclass) {        if (typeof (oclass) == "string")            return document.getElementsByClassName(oclass);        return oclass;    }};// tab切换调用var tabChange = new TabChange();var Lists = document.getElementsByClassName('tabLi');var cons = document.getElementsByClassName('TabCon');tabChange.on(Lists, cons, 'tabLi tabON', 'tabLi');