JavaScript之实例
<meta charset="UTF-8"> <meta http-equiv="x-ua-compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>定时器</title> <script> var intervalId; function f() { var timeStr = (new Date()).toLocaleString(); var inputEle = document.getElementById("i1"); inputEle.value = timeStr; } function start() { f(); if (intervalId === undefined) { intervalId = setInterval(f, 1000); } } function end() { clearInterval(intervalId); intervalId = undefined; } </script> </head> <body> <input type="text" id="i1"> <input type="button" value="开始" id="start" onclick="start();"> <input type="button" value="结束" id="end" onclick="end();"> </body> </html>
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>搜索框示例</title> </head> <body> <input id="d1" type="text" value="请输入关键字" onblur="blurs()" onfocus="focus()"> <script> function focus(){ var inputEle=document.getElementById("d1"); if (inputEle.value==="请输入关键字"){ inputEle.value=""; } } function blurs(){ var inputEle=document.getElementById("d1"); var val=inputEle.value; if(!val.trim()){ inputEle.value="请输入关键字"; } } </script> </body> </html>
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="UTF-8"> <meta http-equiv="x-ua-compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>select联动</title> </head> <body> <select id="province"> <option>请选择省:</option> </select> <select id="city"> <option>请选择市:</option> </select> <script> data = {"河北省": ["廊坊", "邯郸"], "北京": ["朝阳区", "海淀区"], "山东": ["威海市", "烟台市"]}; var p = document.getElementById("province"); var c = document.getElementById("city"); for (var i in data) { var optionP = document.createElement("option"); optionP.innerHTML = i; p.appendChild(optionP); } p.onchange = function () { var pro = (this.options[this.selectedIndex]).innerHTML; var citys = data[pro]; // 清空option c.options.length = 0; for (var i=0;i<citys.length;i++) { var option_city = document.createElement("option"); option_city.innerHTML = citys[i]; c.appendChild(option_city); } } </script> </body> </html>