<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</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>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<script>
var txt = "Hello World!";
document.write("<p>" + txt.length + "</p>");
var txt="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
document.write("<p>" + txt.length + "</p>");
</script>
</body>
</html>
<! DOCTYPE HTML>
<HTML>
<head>
<Meta charset = "UTF-. 8">
<title> novice tutorial (runoob.com) </ title>
</ head>
<body>
<P ID = "Demo"> </ P>
<Script> var X = "John"; // X is a string var Y = new new string ( "John"); // Y is a target
. document.getElementById ( "Demo") the innerHTML = typeof + X "" + typeof Y;
</ Script>
</ body>
</ HTML>
<! DOCTYPE HTML>
<HTML>
<head>
<Meta charset = "UTF-. 8">
<title> novice tutorial (runoob.com) </ title>
</ head>
<body>
<P ID = "Demo"> </ P>
<Script> var X = "John"; // X is a string var Y = new new string ( "John"); // Y is a target
. document.getElementById ( "demo") innerHTML = x = == Y;
</ Script>
<P> === absolute equal, i.e., data type and value must be equal. </ P>
</ body>
</ HTML>
