15.
题目:
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参考以下示例代码,读取页面上已有的source列表,从中提取出城市以及对应的空气质量
将数据按照某种顺序排序后,在resort列表中按照顺序显示出来
分析:
主要知识点: 数组排序,DOM操作1
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/**
* getData方法
* 读取id为source的列表,获取其中城市名字及城市对应的空气质量
* 返回一个数组,格式见函数中示例
*/
function getData() {
var source = document.getElementById("source");
var arrLi = source.getElementsByTagName("li");
var data = [];
var str = "";
for (var i = 0, len = arrLi.length; i < len; i++) {
data[i] = [];
str = arrLi[i].innerHTML;
data[i][0] = str.substring(0, 2);
data[i].push(parseInt(arrLi[i].getElementsByTagName("b")[0].innerHTML));
}
console.log(data);
return data;
}
/**
* sortAqiData
* 按空气质量对data进行从小到大的排序
* 返回一个排序后的数组
*/
function sortAqiData(data) {
function compare(value1, value2) {//二维数组排序
return value1[1] - value2[1];
}
data.sort(compare);
console.log(data);
return data;
}
/**
* render
* 将排好序的城市及空气质量指数,输出显示到id位resort的列表中
* 格式见ul中的注释的部分
*/
function render(data) {
var resort = document.getElementById("resort");
var str = "";
for (var i = 0, len = data.length; i < len; i++) {
str += "<li>第"+ transfer((i + 1).toString()) + "名:" + data[i][0] + "空气质量:" + "<b>" + data[i][1] + "</b></li>";
}
resort.innerHTML = str;
}
function transfer(num) {
var input = String(num);
var unit = ["", "十", "百", "千", "万", "十", "百", "千", "亿"];
var chineseNum = ["零", "一", "二", "三", "四", "五", "六", "七", "八", "九"];
var l = input.length;
var a = [];
var b = [];
var result = "";
for (var i = 0; i < l; i++) {
a[i] = input.substr(i, 1);
b[i] = chineseNum[a[i]];
result += b[i] + unit[l - i - 1];
}
return result;
}
function btnHandle() {
var aqiData = getData();
aqiData = sortAqiData(aqiData);
render(aqiData);
}
function init() {
var btn = document.getElementById("sort-btn");
addEvent(btn, "click", function () {
btnHandle();
});
}
function addEvent(element, type, handler) {
if (element.addEventListener) {
element.addEventListener(type, handler, false);
} else if (element.attachEvent) {
element.attachEvent("on" + type, handler);
} else {
element["on" + type] = handler;
}
}
init();