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<head> <title> </title> <style> .lei{ color: #000; } </style> </head> <body> <!--变字体颜色--> <script type="text/javascript"> function myFunction(){ var x=document.getElementById("demo"); } </script> <input id="demo" type="text"> <button type="button" οnclick="myFunction()">点击变颜色</button><br/> <!--设置类改变字体颜色--> <p class="test">原来是黑色的, 通过js变蓝</p> <script type="text/javascript"> window.onload = function(){ var e = document.getElementsByClassName("test"); e[0].style.color = "blue"; } </script> <!--isNaN判断是不是--> <script type="text/javascript"> function test(){ alert(isNaN(2)); alert(isNaN(3.2)); alert(isNaN("2")); alert("判断=========="); var a=0; alert(a=2); alert(a=="2"); alert(a==="2"); } </script> <p οnclick="test()">isNaN判断是不是</p> <!--innerHTML的用法--改变现有对象，重新赋值--> <script type="text/javascript"> function gaibian(){ document.getElementById('gai').innerHTML="我是改变后的值01"; document.getElementById('bian').innerHTML="我是改变后的值02"; </script> <p id="gai">改变前01</p> <div id="bian">改变前02</div> <button type="button" οnclick="gaibian()">点我改变</button><br/> <!--变量的应用--> <script type="text/javascript"> function test02(){ var i,s,c; i=5; s=6; c=8; alert(i); alert(s+c); alert("2"+2);//字符串2 2 } </script> <input type = "button" value="变量的应用！" οnclick="test02()"><br/> <!--循环数组--> <script> var i ; var canvas = new Array("Audi","BMW","Volvo"); for(i = 0;i<canvas.length;i++){ document.write(canvas[i]+"<br/>"); } </script> <!--获取当前日期函数--> <script type="text/javascript"> document.write(Date()) </script><br/> <!--获取当前周几--> <button onclick = "cha()">今天星期几？</button> <p id = "hao"></p> <script> function cha(){ var x; var d = new Date().getDay(); switch(d){ case 0: x = "今天星期天"; break; case 1: x = "今天星期一"; break; case 2: x = "今天星期二"; break; case 3: x = "星期三"; break; case 4: x = "今天星期四"; break; case 5: x = "今天星期五"; break; case 0: x = "今天星期六"; break; default : x="此日期不存在"; } document.getElementById("hao").innerHTML=x; } </script> <!--数组，声明的同时赋值--> <p id = "hao"></p> <button onclick = "xun()">数组</button> <script> function xun(){ var mycars=new Array("Saab","Volvo","BMW"); document.getElementById("hao").innerHTML=mycars; } </script> <!--定义对象--> <p>定义对象</p> <script> person={firstname:"Bill",lastname:"gates",age:56,eyecolor:"blue"} document.write(person.firstname + " is " + person.age + " years old."); </script><br/> <!--替换字符串--> <script type="text/javascript"> var str="i love you"; alert("i love you".length) alert(str.length); alert(str.indexOf("i ")); alert(str.replace("i","爱你")) alert(str.search("yo")); </script> <!--调用对象，属性，方法--> <script type="text/javascript"> function testE(){ var user = new Object(); user.userId="01"; user.username="zhangsan"; user.password="123456"; user.flag="0"; user.alertAll=function(){ alert("用户id为："+user.userId+"用户名："+user.username+"用户密码为："+user.password+"状态："+user.flag); } user.alertAll(); } </script> <!--函数传参--> <button οnclick="chuancan()">点这里传参</button> <script> function chuancan(){ alert(3+2); } </script> <!--函数传参扩展式--> <p>本例调用的函数会执行一个计算，然后返回结果：</p> <p id="de"></p> <script> function myFunction(a,b) { return a*b; } document.getElementById("de").innerHTML=myFunction(4,3); </script> <!--点击下面的按钮来显示今天是周几--> <p>点击下面的按钮来显示今天是周几：</p> <button οnclick="cha()">点击这里</button> <p id="hd"></p> <script> function cha(){ var x; var d = new Date().getDay(); switch(d){ case 0: x = "星期天"; break; case 1: x = "星期一"; break; case 2: x = "星期二"; break; case 3: x = "星期三"; break; case 4: x = "星期四"; break; case 5: x = "星期五"; break; case 0: x = "星期六"; break; default : x="此日期不存在"; } document.getElementById("hd").innerHTML=x; } </script> </body> </html>