20220712_第七小组_张红睿_学习笔记

javascript 文章 2022-07-15 14:28 0 全屏看文

知识点

JavaScript部分函数

Array:

  • concat():连接两个数组。
  • join():设置分隔符连接数组成一个字符串。
  • pop():删除最后一个元素。
  • sort():排序

Global:

  • isNaN():判断一个值是不是数字。
  • parseInt():转换成整数。
  • parseFloat():转换成浮点数。
  • number():转换成数值对象。
  • string():转换成字符串。

String:

  • charAt():取出指定位置的字符
  • indexOf():判断指定的字符是否生效、如果已存在返回下标
  • lastIndexOf('a'):从后往前找
  • replace('a', 'b'):替换字符串
  • split('-'):根据-去拆分字符串,得到一个数组
  • subString(1, 6):字符串截取

Math:

  • ceil()向上取整
  • floor()z向下取整
  • round()四舍五入
  • random()随机,生成一个0~1的随机数

JS 主要事件

onclick:鼠标点击事件

ondblclick:鼠标双击事件

onblur:失去焦点(一般作用与文本框上)

onfocus:获得焦点

onchange:元素内容改变事件

onload:加载事件

实践

​ 实现三元联动的省市区选择功能。

源代码

Html:
点击查看代码
<!DOCTYPE html><html lang="en"><head>    <meta charset="UTF-8">    <meta http-equiv="X-UA-Compatible" content="IE=edge">    <meta name="viewport" content="width=device-width, initial-scale=1.0">    <title>三元联动</title>    <link rel="stylesheet" href="../css/work.css" type="text/css"></head><body>    <div>        <select id="province" onchange="changeProvince()">            <option value="">---请选择省---</option>            <option value="JiLin">吉林省</option>            <option value="LiaoNing">辽宁省</option>            <option value="HeiLongJiang">黑龙江省</option>        </select>        <select id="city" onchange="changeCity()">            <option value="">---请选择市---</option>        </select>        <select id="district">            <option value="">---请选择区---</option>        </select>    </div>    <script type="text/javascript" src="../js/work.js"></script></body></html>
CSS:
点击查看代码
div{    width: 700px;    margin: 0 auto;}select{    width: 200px;    height: 50px;    background-color: lightskyblue;}select, option{    font-size: 20px;    text-align: center;}option{    background-color: lightcoral;}
JavaScript:
点击查看代码
let defaultCityHtml = '';let defaultDistrictHtml = '';let province_JiLin_E = ['ChangChun', 'JiLin', 'SiPing', 'LiaoYuan', 'TongHua', 'BaiShan', 'SongYuan', 'BaiCheng', 'YanBian'];let province_JiLin_C = ['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'];let province_LiaoNing_E = ['ShenYang', 'DaLian', 'AnShan', 'FuShun', 'BenXi', 'DanDong', 'JinZhou', 'YingKou', 'FuXin', 'LiaoYang', 'PanJin', 'TieLing', 'ChaoYang', 'HuLuDao'];let province_LiaoNing_C = ['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'];let province_HeiLongJiang_E = ['HaErBin', 'QiQiHaEr', 'JiXi', 'HeGang', 'ShuangYaShan', 'DaQing', 'YiChun', 'JiaMuSi', 'QiTaiHe', 'MuDanJiang', 'HeiHe', 'SuiHua', 'DaXingAnLing'];let province_HeiLongJiang_C = ['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', '大兴安岭市'];//吉林省市 区let city_ChangChun_C = ['南关区', '宽城区', '朝阳区', '二道区', '绿园区', '双阳区', '九台区'];let city_JiLin_C = ['昌邑区', '龙潭区', '船营区', '丰满区'];let city_SiPing_C = ['铁西区', '铁东区'];let city_LiaoYuan_C = ['龙山区', '西安区'];let city_TongHua_C = ['东昌区', '二道江区'];let city_BaiShan_C = ['浑江区', '江源区'];let city_SongYuan_C = ['宁江区'];let city_BaiCheng_C = ['洮北区'];let city_YanBian_C = ['延吉市', '图们市', '敦化市', '珲春市', '龙井市', '和龙市', '汪清县', '安图县'];//辽宁省市 区let city_ShenYang_C = ['和平区', '沈河区', '大东区', '皇姑区', '铁西区', '苏家屯区', '浑南区', '沈北新区', '于洪区', '辽中区'];let city_DaLian_C = ['中山区', '西岗区', '沙河口区', '甘井子区', '旅顺口区', '金州区', '普兰店区'];let city_AnShan_C = ['铁东区', '铁西区', '立山区', '千山区'];let city_FuShun_C = ['新抚区', '望花区', '顺城区'];let city_BenXi_C = ['平山区', '溪湖区', '明山区', '南芬区'];let city_DanDong_C = ['元宝区', '振兴区', '振安区'];let city_JinZhou_C = ['古塔区', '凌河区', '太和区'];let city_YingKou_C = ['站前区', '西市区', '鲅鱼圈区', '老边区'];let city_FuXin_C = ['海州区', '新邱区', '太平区', '清河门区', '细河区'];let city_LiaoYang_C = ['白塔区', '文圣区', '宏伟区', '弓长岭区', '太子河区'];let city_PanJin_C = ['双台子区', '兴隆台区', '大洼区'];let city_TieLing_C = ['银州区', '清河区'];let city_ChaoYang_C = ['双塔区', '龙城区'   ];let city_HuLuDao_C = ['连山区', '龙港区', '南票区'];//黑龙江省市 区let city_HaErBin_C = ['道里区', '南岗区', '道外区', '平房区', '松北区', '香坊区', '呼兰区', '阿城区', '双城区'];let city_QiQiHaEr_C = ['龙沙区', '建华区', '铁锋区', '昂昂溪区', '富拉尔基区', '碾子山区', '梅里斯达斡尔族区'];let city_JiXi_C = ['鸡冠区', '恒山区', '滴道区', '梨树区', '城子河区', '麻山区'];let city_HeGang_C = ['向阳区', '工农区', '南山区', '兴安区', '东山区', '兴山区'];let city_ShuangYaShan_C = ['尖山区', '岭东区', '四方台区', '宝山区'];let city_DaQing_C = ['萨尔图区', '龙凤区', '让胡路区', '红岗区', '大同区'];let city_YiChun_C = ['伊美区', '乌翠区', '友好区', '金林区'];let city_JiaMuSi_C = ['向阳区', '前进区', '东风区', '郊区'];let city_QiTaiHe_C = ['新兴区', '桃山区', '茄子河区'];let city_MuDanJiang_C = ['东安区', '阳明区', '爱民区', '西安区'];let city_HeiHe_C = ['爱辉区'];let city_SuiHua_C = ['北林区'];let city_DaXingAnLing_C = ['加格达奇区', '松岭区', '新林区', '呼中区', '漠河市', '呼玛县', '塔河县'];function changeProvince(){    let province = document.querySelector("#province").value;    let city = document.querySelector("#city");    let district = document.querySelector("#district");    defaultCityHtml == ''        ? (defaultCityHtml = city.innerHTML)       : (city.innerHTML = defaultCityHtml);    defaultDistrictHtml == ''       ? (defaultDistrictHtml = district.innerHTML)       : (district.innerHTML = defaultDistrictHtml);        if (province == "JiLin") {        for (let e = 0, c = 0; e < province_JiLin_E.length && c < province_JiLin_C.length; e++, c++){            city.innerHTML += '<option value="' + province_JiLin_E[e] + '">' + province_JiLin_C[c] + '</option>'        }    }else if (province == "LiaoNing") {        for (let e = 0, c = 0; e < province_LiaoNing_E.length && c < province_LiaoNing_C.length; e++, c++){            city.innerHTML += '<option value="' + province_LiaoNing_E[e] + '">' + province_LiaoNing_C[c] + '</option>'        }    }else if (province == "HeiLongJiang"){        for (let e = 0, c = 0; e < province_HeiLongJiang_E.length && c < province_HeiLongJiang_C.length; e++, c++){            city.innerHTML += '<option value="' + province_HeiLongJiang_E[e] + '">' + province_HeiLongJiang_C[c] + '</option>'        }    }}function changeCity(){    let province = document.querySelector("#province").value;    let city = document.querySelector("#city");    let district = document.querySelector("#district");    defaultDistrictHtml == ''        ? (defaultDistrictHtml = district.innerHTML)       : (district.innerHTML = defaultDistrictHtml);    switch (city.value) {        // 吉林        case "ChangChun":            for (value of city_ChangChun_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "JiLin":            for (value of city_JiLin_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "SiPing":            for (value of city_SiPing_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "LiaoYuan":            for (value of city_LiaoYuan_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "TongHua":            for (value of city_TongHua_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "BaiShan":            for (value of city_BaiShan_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "SongYuan":            for (value of city_SongYuan_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "BaiCheng":            for (value of city_BaiCheng_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "YanBian":            for (value of city_YanBian_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        // 辽宁        case "ShenYang":            for (value of city_ShenYang_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "DaLian":            for (value of city_DaLian_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "AnShan":            for (value of city_AnShan_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "FuShun":            for (value of city_FuShun_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "BenXi":            for (value of city_BenXi_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "DanDong":            for (value of city_DanDong_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "JinZhou":            for (value of city_JinZhou_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "YingKou":            for (value of city_YingKou_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "FuXin":            for (value of city_FuXin_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "LiaoYang":            for (value of city_LiaoYang_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "PanJin":            for (value of city_PanJin_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "TieLing":            for (value of city_TieLing_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "ChaoYang":            for (value of city_ChaoYang_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "HuLuDao":            for (value of city_HuLuDao_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;   // 黑龙江         case "HaErBin":            for (value of city_HaErBin_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "QiQiHaEr":            for (value of city_QiQiHaEr_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "JiXi":            for (value of city_JiXi_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "HeGang":            for (value of city_HeGang_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "ShuangYaShan":            for (value of city_ShuangYaShan_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "DaQing":            for (value of city_DaQing_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "YiChun":            for (value of city_YiChun_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "JiaMuSi":            for (value of city_JiaMuSi_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "QiTaiHe":            for (value of city_QiTaiHe_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "MuDanJiang":            for (value of city_MuDanJiang_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "HeiHe":            for (value of city_HeiHe_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "SuiHua":            for (value of city_SuiHua_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;        case "DaXingAnLing":            for (value of city_DaXingAnLing_C) {   district.innerHTML += '<option value="' + value + '"> ' + value + '</option>';            }            break;            default:            break;    }}

效果截图:

-EOF-