JavaScript 变量定义及使用-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_40181214/article/details/79990695

答：

<html>
<head>
<meta charset="utf-8"> 
<title>菜鸟教程(runoob.com)</title> 
<script>
function myFunction(){
	var a = 10;
	var b = 2.5;//数字
	var s = 'jark';
	var t = "meriy";//字符
	var ar = [40, 100, 1, 5, 25, 10];//数组
	var jo = '{firstName:"John", lastName:"Doe", age:50, eyeColor:"blue"}';//josn字符串
	var jos = {firstName:"John", lastName:"Doe", age:50, eyeColor:"blue"};//josn对象
	document.getElementById("a").innerHTML=  a*b;
	document.getElementById("b").innerHTML=  s;
	document.getElementById("c").innerHTML=  a+"-"+t;
	document.getElementById("d").innerHTML=  ar[3];
	var obj = eval('(' + jo + ')');	
	//var obj = str.parseJSON(); //由JSON字符串转换为JSON对象
	document.getElementById("e").innerHTML=  obj.firstName;
	document.getElementById("f").innerHTML=  jos.eyeColor;
	document.write("你好  <br> 世界!");//输出换行
}
</script>
</head>
<body>
	
<h1>我的 Web 页面</h1>
<label id="a"></label>
<label id="b"></label>
<label id="c"></label>
<label id="d"></label>
<label id="e"></label>
<label id="f"></label>
 <button type="button" οnclick="myFunction()">点击赋值</button>
	
</body>
</html>