01-变量
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<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script>
var age;
age = 18;
console.log(age);
var myname = 'pink';
console.log(myname);
</script>
</head>
<body>
</body>
</html>
02-变量案例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script>
var myname = '旗木卡卡西';
var adress = '火影村';
var age = 30;
var email = 'kakaxi@itcast.cn';
var gz = 2000;
console.log(myname);
console.log(adress);
console.log(age);
console.log(email);
console.log(gz);
</script>
</head>
<body>
</body>
</html>
效果展示

03-弹出用户名案例
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<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script>
var myname = prompt('请输入您的姓名');
alert(myname);
</script>
</head>
<body>
</body>
</html>
04-变量的语法拓展
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<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>变量的语法扩展</title>
<script>
var myname = 'pink老师';
console.log(myname);
myname = '迪丽热巴';
console.log(myname);
var age = 18,
address = '火影村',
gz = 2000;
var sex;
console.log(sex);
qq = 110;
console.log(qq);
</script>
</head>
<body>
</body>
</html>
05-变量命名规范
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<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script>
var app = 10;
var APP = 100;
console.log(app);
console.log(APP);
console.log(name);
</script>
</head>
<body>
</body>
</html>
06-交换两个变量值
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script>
var temp;
var apple1 = '青苹果';
var apple2 = '红苹果';
temp = apple1;
apple1 = apple2;
apple2 = temp;
console.log(apple1);
console.log(apple2);
</script>
</head>
<body>
</body>
</html>
07-变量总结
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<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>变量总结</title>
<script>
</script>
</head>
<body>
<h4>1.为什么需要变量</h4>
<p>因为我们一些数据需要保存,所以需要变量</p>
<h4>2.变量是什么</h4>
<p>变量就是一个容器,用来存放数据的。方便以后我们使用里面的数据</p>
<h4>3.变量的本质</h4>
<p>变量是内存里的一块空间,用来存储数据</p>
<h4>4.变量的使用</h4>
<p>我们使用变量的时候,先声明变量,再赋值。</p>
<p>声明变量的本质是去内存申请空间</p>
<h4>5.什么是变量的初始化</h4>
<p>声明变量并赋值称之为变量的初始化</p>
<h4>6.变量的命名规范</h4>
<p>变量名要规范,见名知意-驼峰命名法</p>
<h4>7.交换2个变量值的思路</h4>
<p>先画图,再写代码。理清思路</p>
</body>
</html>
效果展示
