Сценарии JavaScript

Сценарий в заголовке страницы.

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<script>
alert("Hello World!");
</script>
</head>
<body>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<script>
alert("Hello World!");
</script>
</head>
<body>
</body>
</html>

Сценарий в теле страницы.

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
</head>
<body>
<script>
alert("Hello World!");
</script>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
</head>
<body>
<script>
alert("Hello World!");
</script>
</body>
</html>

Сценарий в теге.

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
</head>
<body>
<button onclick="alert('Hello World!')">OK</button>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
</head>
<body>
<button onclick="alert('Hello World!')">OK</button>
</body>
</html>

Сценарий во внешнем файле.

script.js

function funMessage() {
alert('Hello World!');
}

function funMessage() {
alert('Hello World!');
}

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<script src="script.js"></script>
</head>
<body>
<script>
funMessage();
</script>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<script src="script.js"></script>
</head>
<body>
<script>
funMessage();
</script>
</body>
</html>