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<!DOCTYPE html>
<html>
<head> 
<meta charset="utf-8"> 
<title>Wfuyu教程(wfuyu.com)</title> 
</head>
<body>
​
<p>点击按钮创建及增加字符串变量。</p>
<button onclick="myFunction()">点击这里</button>
<p id="demo"></p>
<script>
function myFunction()
{
    var x=5+5;
    var y="5"+5;
    var z="Hello"+5;
    var demoP=document.getElementById("demo");
    demoP.innerHTML=x + "<br>" + y + "<br>" + z;
}
</script>
​
</body>
</html>