A. WEB前端学习五 js什么是引用类型
三大引用类型，对象，数组，函数。引用类型和基本类型主要区别是引用类型存的是地址，但其实在JS中 万事万物皆对象，本质上来讲大家都可以算对象
B. 前端JS模板可定义在其他文件并引用吗
可以的，引用的文件有用就行
C. web前端 响应式开发关于引用js文件的问题
可以考虑动态加载，在JS中判断，再用 document.write("<script...
来动态加载JS文件，很多JS框架使用动态加载.
D. rem的前端页面引用插件是px怎么办
多年的前端开发实践中经历了从最初的PC固定布局、手机端固定布局（两端留白）到响应式设计（媒体查询、百分比布局等），直到最终选择rem+Javascript的模式，但是在项目开发中需要将大量的样式由px转换为rem，单位之间的换算虽然不复杂，但是工作量却很大。那么能不能有一种自动化的解决方案呢？通过搜索，找到了一种方案。读者可以直接在网络搜索引擎中搜索“用grunt写了一个px和rem互转的工具”，点击图中用边框标示的部分，进入“用grunt写了一个px和rem互转的工具”页面，在该文章的末尾还提供了一个在线转换工具，如下图所示，可以很方便地将px转换为rem，批量操作，几秒就能完成。笔者将实际项目中的CSS代码拷贝进入转换，有几个参数要选择，进行转换效果如这里的参数选择和你在项目中的设计图尺寸和根元素字体大小相关，至于border的处理是因为在安卓下使用rem单位的支持性特别差，你可能写2rem或者3rem都没用默认会变成1px，所以在使用border属性时很多时候不建议处理border。Javascript控制根元素大小的代码读者可以将代码放在公共的Js文件中，确保每个HTML文件都引用到。在线工具中还提供了自动生成媒体查询的功能，这在响应式设计中可以少些许多CSS代码，让前端开发事半功倍。这里不做介绍，读者根据实际情况决定是否使用该功能。其实，读者也可以自己写一个javascript函数实现上述功能，不过，重复发明轮子也没有什么意义，除了上面的工具之外（javascript实现），还有Sass的方案。网络有相关的文章，读者可以去研读，不过，还是在线工具为最佳，当然也可以将该工具下载下来使用。
E. web前端怎么引用jquery省市级联插件
1.[代码]新增选择城市
$(function(){
$("#province").cityCasCade("#city").cityCasCade('select','河南省');
//or
$("#province").cityCasCade("#city").cityCasCade('select','河南省','开封市');
}
/**
*javadiqye
*城市数据时从网上Copy的
*级联功能也是参考网上已做好的思路
*封装成插件为了以后使用方便
*add增加选中城市方法select
*/
(function($){
$.fn.cityCasCade=function(operation,province,city){
varselectCity=null,params=null,overparams=null;
if(typeofoperation=="string"){
if(operation=="select"){
if(province){
$(this).find("option").each(function(){
if($(this).val()==province){
this.selected=true;
$(this).change();
if(city){
$($.fn.cityCascadeParam.selectCity).find("option").each(function(){
if($(this).val()==city){
this.selected=true;
$(this).change();
}
});
}
}
});
}
return$(this);
}
selectCity=operation;
}
else{
if(operation.selector)selectCity=operation.selector;
if(operation.overide&&operation.data)overparams=operation.data;
elseparams=operation.data;
}
$.fn.cityCascadeParam={};
$.fn.cityCascadeParam.data=_provinces_;
$.fn.cityCascadeParam.selectCity=null;
if(selectCity)$.fn.cityCascadeParam.selectCity=selectCity;
elsethrow"城市选择器不能为空";
$.fn.cityCascadeParam.cityValue=$($.fn.cityCascadeParam.selectCity+":first").val();
$.fn.cityCascadeParam.cityText=$($.fn.cityCascadeParam.selectCity+":first").text();
if(overparams)$.fn.cityCascadeParam.data=overparams;
else$.extend($.fn.cityCascadeParam.data,params);
$.fn.cityCascadeParam.loadProvince=function(self){
for(varpin$.fn.cityCascadeParam.data){
varopt=document.createElement("option");
opt.innerHTML=p;
opt.value=p;
self.appendChild(opt);
}
}
$.fn.cityCascadeParam.loadCity=function(parent){
varself=$($.fn.cityCascadeParam.selectCity).get(0);
if(!self)throw"未找到城市下拉框城市选择器>>"+$.fn.cityCascadeParam.selectCity;
varselectProvince=$(parent).val();
if(selectProvincein$.fn.cityCascadeParam.data){
varcitys=$.fn.cityCascadeParam.data[selectProvince];
self.innerHTML="";
for(varindex=0;index<citys.length;index++){
opt=document.createElement("option");
opt.innerHTML=citys[index];
opt.value=citys[index];
self.appendChild(opt);
}
}else{
self.innerHTML="";
opt=document.createElement("option");
opt.innerHTML=$.fn.cityCascadeParam.cityText;
opt.value=$.fn.cityCascadeParam.cityValue;
self.appendChild(opt);
}
}
this.each(function(){
$.fn.cityCascadeParam.loadProvince(this);
$(this).change(function(){
$.fn.cityCascadeParam.loadCity(this);
});
});
return$(this);
}
})($);
var_provinces_={四川省:["成都市","自贡市","攀枝花市","泸州市","德阳市","绵阳市","广元市","遂宁市","内江市","乐山市","南充市","眉山市","宜宾市","广安市","达州市","雅安市","巴中市","资阳市","阿坝藏族羌族自治州","甘孜藏族自治州","凉山彝族自治州"],山西省:["太原市","大同市","阳泉市","长治市","晋城市","朔州市","晋中市","运城市","忻州市","临汾市","吕梁市"],内蒙古:["呼和浩特市","包头市","乌海市","赤峰市","通辽市","鄂尔多斯市","呼伦贝尔市","巴彦淖尔市","乌兰察布市","兴安盟","锡林郭勒盟","阿拉善盟"],辽宁省:["沈阳市","大连市","鞍山市","抚顺市","本溪市","丹东市","锦州市","营口市","阜新市","辽阳市","盘锦市","铁岭市","朝阳市","葫芦岛市"],吉林省:["长春市","吉林市","四平市","辽源市","通化市","白山市","松原市","白城市","延边朝鲜族自治州"],黑龙江省:["哈尔滨市","齐齐哈尔市","鸡西市","鹤岗市","双鸭山市","大庆市","伊春市","佳木斯市","七台河市","牡丹江市","黑河市","绥化市","大兴安岭地区"],上海:["上海"],江苏省:["南京市","无锡市","徐州市","常州市","苏州市","南通市","连云港市","淮安市","盐城市","扬州市","镇江市","泰州市","宿迁市"],浙江省:["杭州市","宁波市","温州市","嘉兴市","湖州市","绍兴市","金华市","衢州市","舟山市","台州市","丽水市"],安徽省:["合肥市","芜湖市","蚌端口市","淮南市","马鞍山市","淮北市","铜陵市","安庆市","黄山市","滁州市","阜阳市","宿州市","巢湖市","六安市","亳州市","池州市","宣城市"],福建省:["福州市","厦门市","莆田市","三明市","泉州市","漳州市","南平市","龙岩市","宁德市"],江西省:["南昌市","景德镇市","萍乡市","九江市","新余市","鹰潭市","赣州市","吉安市","宜春市","抚州市","上饶市"],山东省:["济南市","青岛市","淄博市","枣庄市","东营市","烟台市","潍坊市","济宁市","泰安市","威海市","日照市","莱芜市","临沂市","德州市","聊城市","滨州市","菏泽市"],河南省:["郑州市","开封市","洛阳市","平顶山市","安阳市","鹤壁市","新乡市","焦作市","濮阳市","许昌市","漯河市","三门峡市","南阳市","商丘市","信阳市","周口市","驻马店市"],湖北省:["武汉市","黄石市","十堰市","宜昌市","襄樊市","鄂州市","荆门市","孝感市","荆州市","黄冈市","咸宁市","随州市","恩施土家族苗族自治州"],湖南省:["长沙市","株洲市","湘潭市","衡阳市","邵阳市","岳阳市","常德市","张家界市","益阳市","郴州市","永州市","怀化市","娄底市","湘西土家族苗族自治州"],广东省:["广州市","韶关市","深圳市","珠海市","汕头市","佛山市","江门市","湛江市","茂名市","肇庆市","惠州市","梅州市","汕尾市","河源市","阳江市","清远市","东莞市","中山市","潮州市","揭阳市","云浮市"],广西省:["南宁市","柳州市","桂林市","梧州市","北海市","防城港市","钦州市","贵港市","玉林市","百色市","贺州市","河池市","来宾市","崇左市"],海南省:["海口市","三亚市"],重庆市:["重庆"],贵州省:["贵阳市","六盘水市","遵义市","安顺市","铜仁地区","黔西南布依族苗族自治州","毕节地区","黔东南苗族侗族自治州","黔南布依族苗族自治州"],云南省:["昆明市","曲靖市","玉溪市","保山市","昭通市","丽江市","思茅市","临沧市","楚雄彝族自治州","红河哈尼族彝族自治州","文山壮族苗族自治州","西双版纳傣族自治州","大理白族自治州","德宏傣族景颇族自治州","怒江傈僳族自治州","迪庆藏族自治州"],西藏自治区:["拉萨市","昌都地区","山南地区","日喀则地区","那曲地区","阿里地区","林芝地区"],陕西省:["西安市","铜川市","宝鸡市","咸阳市","渭南市","延安市","汉中市","榆林市","安康市","商洛市"],甘肃省:["兰州市","嘉峪关市","金昌市","白银市","天水市","武威市","张掖市","平凉市","酒泉市","庆阳市","定西市","陇南市","临夏回族自治州","甘南藏族自治州"],青海省:["西宁市","海东地区","海北藏族自治州","黄南藏族自治州","海南藏族自治州","果洛藏族自治州","玉树藏族自治州","海西蒙古族藏族自治州"],宁夏自治区:["银川市","石嘴山市","吴忠市","固原市","中卫市"],新疆自治区:["乌鲁木齐市","克拉玛依市","吐鲁番地区","哈密地区","昌吉回族自治州","博尔塔拉蒙古自治州","巴音郭楞蒙古自治州","阿克苏地区","克孜勒苏柯尔克孜自治州","喀什地区","和田地区","伊犁哈萨克自治州","塔城地区","阿勒泰地区"],台湾省:["台北市"],香港特区:["香港"],澳门特区:["澳门"],河北省:["石家庄","唐山","秦皇岛","张家口","承德","廊坊","邯郸","邢台","保定","沧州","衡水"]};
F. 前端开发，引用别人建的组建，怎么修改相关内容
主要看你引用的是开发版本还是上线版本。。上线版本一般都是压缩后的也就是.min.js后缀的。。开发版本源码看着比较清晰。。你可以找到开发版本修改，上线时候如需要再压缩
G. 前端开发如何引用插件
一般的插件都是有自己的CSS和JS文件的，你直接把它们加载你的head里，如下：
<script src="你找到的插件提供的JS文件地址">
如果你在用J2EE或者，C#MVC框架开发web应用系统的话，有一个神器推荐给你--“活字格”，绝对好用。另外，就是任何的插件都是有说明文档的你看他的说明文档怎么用。
还有，做为一个开发者，纠正你一个名词，这个一般叫控件不叫插件 。
H. 前端Vue+Element 框架怎么引用Echars创建柱线混合图，如下图
npm 安装 然后在需要用echart的地方引用就行了。跟引用组件的方式一样
npm install echarts --save
I. 前端引入和引用的区别
href 表示超文本引用（hypertext reference），在 link和a 等元素上使用。src 表示来源地址，在 img、script、iframe 等元素上。
src 的内容，是页面必不可少的一部分，是引入。href 的内容，是与该页面有关联，是引用。区别就是，引入和引用。
J. 前端开发，关于引用第三方开源插件有什么要求
name决定模块的名称，不允许与npm社区中的已发布模块同名，模块发布后，其他开发者可以通过该名称安装该模块。
version需遵循语义化版本规范，格式为[MAJOR].[MINOR].[PATCH]，分别代表主版本，次版本，补丁版本，可以通过执行npm version命令自动更替版本。
main表示模块的入口文件，用户通过require('example')加载该入口文件。