js基本语法1

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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Javascript语法</title>
<script src="myjs.js" type="text/javascript" language="javascript"></script>
<script>
//变量：JAVA强语言类型，js 是弱语言类型（不强调数据类型）
//描述一个学生的基本信息
//基本数据类型
var name = "张三";
var age = 22;
var height = 1.75;
var sex = '男';
var hasGirlfriend = true;

//对象类型（引用类型）:1系统对象，2自定义对象
//系统对象
var string = new String("你好");
var date = new Date();
var nums = new Array();

//自定义对象var obj = new Object()
var student = new Object();
student.age = 20;
student.name = "李四";
student.sex = '男';

//输出
document.writeln("一句话");
document.writeln(student.name);

//程序结构
//if
if(2<1){
document.writeln("正确");
}else if(2==0){
document.writeln("正确1");
}else{
document.writeln("正确2");
}

//for
for(var i = 0;i<5;i++){
document.writeln(i);
}

//2.计算:算术运算符
var one = 1;
var two = 2;
var three = "3";
document.writeln(one+two+"<br/>");
document.writeln(one+parseInt(three));

var four = 10;
//four += 4;
four = four + 4;
document.writeln(four);

//3.逻辑运算符
document.writeln(!3>2||4<3);
document.writeln("<br/>");

//4.系统对象的运用
document.writeln(date.getYear()+1900+"年");
document.writeln(date.getMonth()+1+"月");
document.writeln(date.getDate()+"日");
document.writeln(date.getHours()+"时");
document.writeln(date.getMinutes()+"分");
document.writeln(date.getSeconds()+"秒");
document.writeln(date.getMilliseconds()+"毫秒");
document.writeln("星期"+date.getDay());
document.writeln("总时间"+date.getTime());

//数组:类型可不一样
nums[0] = 10;
nums[1] = 20;
nums[2] = 30;
nums[3] = "40";

//输出
for(var i =0;i<nums.length;i++){
document.writeln(nums[i]+"<br/>");
}
//1.练习语法
//2.1.通过JS打印一下你出生时的日期信息
var date = new Date();
date.setFullYear(1994,2,7);
date.setHours(23,45,27,36);
document.writeln("出生信息是：");
document.writeln(date.getYear()+1900+"年");
document.writeln(date.getMonth()+"月");
document.writeln(date.getDate()+"日");
document.writeln(date.getHours()+"时");
document.writeln(date.getMinutes()+"分");
document.writeln(date.getSeconds()+"秒");
document.writeln(date.getMilliseconds()+"毫秒");
document.writeln("星期"+date.getDay());

//2.2 通过数据，存储10种颜色，打印出这10种颜色
document.writeln("<br/>");
var colors = new Array("红","橙","黄","绿","蓝","靛","紫","粉","黑","白");
for(var i =0;i<colors.length;i++){
document.writeln(colors[i]+"<br/>");
}

//2.3自定义一个对象类型，然后存储学生信息，然后打印出来……
var student = new Object();
student.name = "李狗蛋";
student.age = 23;
student.sex = '男';
student.hasGirlfriend = false;
document.writeln("姓名："+student.name+"<br/>");
document.writeln("年龄："+student.age+"<br/>");
document.writeln("性别："+student.sex+"<br/>");
document.writeln("有没有女朋友："+student.hasGirlfriend+"<br/>");

//2.4JS程序逻辑，生成随机数10个，存放在数据里面，然后累加起来……打印结果
var numbers = new Array(10);
var total =0;
for(var i =0;i<numbers.length;i++){
numbers[i]=parseInt(Math.random()*10);
}
for(var i = 0;i<numbers.length;i++){
document.writeln(numbers[i]+"<br/>");
total+=numbers[i];
}
document.writeln(total);

</script>
</head>

<body>
</body>
</html>

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