时间：2021-07-01 10:21:17 帮助过：34人阅读
1.运算符
var box1=100;
++box1;//相当于box=box+1
document.write("box1="+box1+"<br/>");//输出box1=101
var box2=100;
--box2;//相当于box=box2-1
document.write("box2="+box2);//输出box2=99推荐大家学习javascript运算符专题，里面有对运算符详细的讲解
2.表达式
<html>
<head>
<meta charset="utf-8">
<title>Gxl网(php.cn)</title>
</head>
<body>
<script>
cars=["小明","小龙","小奇","小涛"];
for (var i=0,l=cars.length; i<l; i++){
document.write(cars[i] + "<br>");
}
</script>
</body>
</html>http://www.gxlcms.com/code/3595.html
3.语句
Javascript语句包括：赋值语句、switch选择语句、while循环语句、for循环语句、for each循环语句、do while循环语句、break循环中止语句、continue循环中断语句、with语句、try...catch语句、if语句（if..else，if...else if ...）、let语句。
<html>
<head>
<meta charset="utf-8">
<title>Gxl网(php.cn)</title>
</head>
<body>
<p>点击下面的按钮来显示今天是周几：</p>
<button onclick="myFunction()">点击这里</button>
<p id="demo"></p>
<script>
function myFunction(){
var x;
var d=new Date().getDay();
switch (d){
case 0:x="今天是星期日";
break;
case 1:x="今天是星期一";
break;
case 2:x="今天是星期二";
break;
case 3:x="今天是星期三";
break;
case 4:x="今天是星期四";
break;
case 5:x="今天是星期五";
break;
case 6:x="今天是星期六";
break;
}
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>http://www.gxlcms.com/code/3601.html
4.函数
<html>
<head>
<meta charset="utf-8">
<title>Gxl网(php.cn)</title>
</head>
<body>
<p>点击这个按钮，来调用带参数的函数。</p>
<button onclick="myFunction('哈利波特','Wizard')">点击这里</button>
<script>
function myFunction(name,job){
alert("Welcome " + name + ", the " + job);
}
</script>
</body>
</html>http://www.gxlcms.com/code/3580.html
5.对象
<html>
<head>
<meta charset="utf-8">
<title>Gxl网（php.cn)</title>
</head>
<body>
<p>创建 JavaScript 对象。</p>
<p id="demo"></p>
<script>
var person = {firstName:"John", lastName:"Doe", age:50, eyeColor:"blue"};
document.getElementById("demo").innerHTML =
person.firstName + " 现在 " + person.age + " 岁.";
</script>
</body>
</html>http://www.gxlcms.com/code/3575.html
6.事件
<html>
<head>
<meta charset="utf-8">
<title>Gxl网(php.cn)</title>
</head>
<body>
<button onclick="getElementById('demo').innerHTML=Date()">现在的时间是?</button>
<p id="demo"></p>
</body>
</html>http://www.gxlcms.com/code/3594.html
7.变量
<html>
<head>
<meta charset="utf-8">
<title>PHP中文网(php.cn)</title>
</head>
<body>
<p>点击这里来创建变量，并显示结果。</p>
<button onclick="myFunction()">点击这里</button>
<p id="demo"></p>
<script>
function myFunction(){
var carname="Volvo";
document.getElementById("demo").innerHTML=carname;
}
</script>
</body>
</html>http://www.gxlcms.com/code/3553.html
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