【代码笔记】Web-JavaScript-JavaScript 变量

一，效果图。

二，代码。

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<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>javascript 变量</title>
</head>

<body>
    <script>
    var x = 5;
    var y = 6;
    var z = x + y;

    document.write(x + "<br>");
    document.write(y + "<br");
    document.write(z = "<br>");
    </script>
    <script>
    var pi = 3.14;
    var name = "bill gate";
    var answer = "yes i am ";

    document.write(pi + "<br>");
    document.write(name + "<br>");
    document.write(answer + "<br>");
    </script>
    <p>点这里来创建变量，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>
    <p>假设 y=5，计算 x=y+2，并显示结果</p>
    <button onclick="myFunction()">点击这里</button>
    <p id="demo"></p>
    <script>
    function myFunction() {
        var y = 5;
        var x = y + 2;
        var demoP = document.getElementById("demo");
        demoP.innerHTML = "x=" + x;
    }
    </script>
</body>

</html>
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参考资料：《菜鸟教程》

posted @ 2018-11-28 09:25  花儿迎风笑  阅读(232)  评论(0)  编辑  收藏  举报