文章目录
- JavaScript 高级实例集合
-
- 创建一个欢迎 cookie
- 简单的计时
- 另一个简单的计时
- 在一个无穷循环中的计时事件
- 带有停止按钮的无穷循环中的计时事件
- 使用计时事件制作的钟表
- 创建对象的实例
- 创建用于对象的模板
JavaScript 高级实例集合
创建一个欢迎 cookie
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>梁辰兴实例</title>
</head>
<head>
<script>
function setCookie(cname,cvalue,exdays){var d = new Date();d.setTime(d.getTime()+(exdays*24*60*60*1000));var expires = "expires="+d.toGMTString();document.cookie = cname+"="+cvalue+"; "+expires;
}
function getCookie(cname){var name = cname + "=";var ca = document.cookie.split(';');for(var i=0; i<ca.length; i++) {var c = ca[i].trim();if (c.indexOf(name)==0) return c.substring(name.length,c.length);}return "";
}
function checkCookie(){var user=getCookie("username");if (user!=""){alert("Welcome again " + user);}else {user = prompt("Please enter your name:","");if (user!="" && user!=null){setCookie("username",user,30);}}
}
</script>
</head>
<body onload="checkCookie()"></body>
</html>
- 运行效果
简单的计时
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>梁辰兴实例</title>
</head>
<body>
<p>点击按钮，在等待 3 秒后弹出 "Hello"。</p>
<button onclick="myFunction()">点我</button>
<script>
function myFunction(){setTimeout(function(){alert("Hello")},3000);
}
</script>
</body>
</html>
- 运行效果
另一个简单的计时
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>梁辰兴实例</title>
</head>
<head>
<script>
function timedText(){var x=document.getElementById('txt');var t1=setTimeout(function(){x.value="2 seconds"},2000);var t2=setTimeout(function(){x.value="4 seconds"},4000);var t3=setTimeout(function(){x.value="6 seconds"},6000);
}
</script>
</head>
<body>
<form>
<input type="button" value="显示文本时间!" onclick="timedText()" />
<input type="text" id="txt" />
</form>
<p>点击上面的按钮，输出的文本将告诉你2秒，4秒，6秒已经过去了。</p>
</body>
</html>
- 运行效果
在一个无穷循环中的计时事件
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>梁辰兴实例</title>
<script>
var c=0;
var t;
var timer_is_on=0;
function timedCount(){document.getElementById('txt').value=c;c=c+1;t=setTimeout("timedCount()",1000);
}
function doTimer(){if (!timer_is_on){timer_is_on=1;timedCount();}
}
</script>
</head>
<body>
<form>
<input type="button" value="开始计数!" onClick="doTimer()">
<input type="text" id="txt">
</form>
<p>单击按钮，输入框将从0开始一直计数。</p>
</body>
</html>
- 运行效果
带有停止按钮的无穷循环中的计时事件
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>梁辰兴实例</title>
<script>
var c=0;
var t;
var timer_is_on=0;
function timedCount(){document.getElementById('txt').value=c;c=c+1;t=setTimeout(function(){timedCount()},1000);
}
function doTimer(){if (!timer_is_on){timer_is_on=1;timedCount();}
}
function stopCount(){clearTimeout(t);timer_is_on=0;
}
</script>
</head>
<body>
<form>
<input type="button" value="开始计数!" onclick="doTimer()" />
<input type="text" id="txt" />
<input type="button" value="停止计数!" onclick="stopCount()" />
</form>
<p>
单击开始计数按钮，按下时开始计数，输入框将从0开始一直计数。单击停止计数按钮，按下时停止计数，再次点击开始计数按钮，又再次开始计数。
</p>
</body>
</html>
- 运行效果
使用计时事件制作的钟表
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>梁辰兴实例</title>
<script>
function startTime(){var today=new Date();var h=today.getHours();var m=today.getMinutes();var s=today.getSeconds();m=checkTime(m);s=checkTime(s);document.getElementById('txt').innerHTML=h+":"+m+":"+s;t=setTimeout(function(){startTime()},500);
}
function checkTime(i){if (i<10){i="0" + i;}return i;
}
</script>
</head>
<body onload="startTime()">
<div id="txt"></div>
</body>
</html>
- 运行效果
创建对象的实例
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>梁辰兴实例</title>
</head>
<body>
<script>
person={firstname:"John",lastname:"Doe",age:50,eyecolor:"blue"}
document.write(person.firstname + " is " + person.age + " years old.");
</script>
</body>
</html>
- 运行效果
创建用于对象的模板
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>梁辰兴实例</title>
</head>
<body>
<script>
function person(firstname,lastname,age,eyecolor){this.firstname=firstname;this.lastname=lastname;this.age=age;this.eyecolor=eyecolor;
}
myFather=new person("John","Doe",50,"blue");
document.write(myFather.firstname + " is " + myFather.age + " years old.");
</script>
</body>
</html>
- 运行效果
