【代码笔记】Web-JavaScript-JavaScript字符串

一，效果图。

二，代码。

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<!DOCTYPE html>
<html>

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

<body>
    <p id="demo"></p>
    <script>
    var x = 'It\'s alright';
    var y = "He is called \"Johnny\"";

    document.getElementById("demo").innerHTML = x + "<br>" + y;
    </script>
    <script>
    var txt = "hello world";
    document.write("<p>" + txt.length + "</p>");

    var txt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    document.write("<p>" + txt.length + "</p>");
    </script>
    <p id="demo"></p>
    <script>
    var x = "John"; // x is a string
    var y = new String("John"); // y is an object

    document.getElementById("demo").innerHTML =
        typeof x + " " + typeof y;
    </script>
    <script>
    var x = "John"; // x 是字符串
    var y = new String("John"); // y 是一个对象
    document.getElementById("demo").innerHTML = x === y;
    </script>
    <p>=== 为绝对相等，即数据类型与值都必须相等。</p>
</body>

</html>
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参考资料：《菜鸟教程》

posted @ 2018-12-07 09:24  花儿迎风笑  阅读(299)  评论(0)  编辑  收藏  举报