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write

This code writes a

tag to the page, which causes the browser to load the external JavaScript

file as it would normally. Note that the string

“</script>”

is split into two parts (

“</scr”

and

“ipt>”

). This is necessary because anytime the browser sees

</script>

, it assumes that the code block

is complete (even if it occurs inside of a JavaScript string). Suppose the previous example were written

without breaking up the

“</script>”

string:

<html>

<head>

<title>Document Example</title>

document.write(“<script type=\”text/javascript\” src=\”external.js\”>”

+ “</script>”); //this will cause a problem

</script>

</head>

<body>

</body>

</html>

The browser views this page as:

<html>

<head>

<title>Document Example</title>

document.write(“<script type=\”text/javascript\” src=\”external.js\”>”

</script>

</head>

<body>

</body>

</html>

As you can see, forgetting to split up the

“</script>”

string causes major confusion. First, there is a

syntax error inside of the

tag because the

document.write()

call is missing its closing

parenthesis. Second, there are two

</script>

tags. This is why you must always break up the

“</script>”

string when writing

tags to the page using

document.write()

Related closely to

write()

and

writeln()

are the

open()

and

close()

methods. The

open()

method

is used to open an already loaded document for writing; the

close()

method is used to close a docu-

ment opened with

open()

, essentially telling it to render everything that was written to it. This combi-

nation of methods is typically used to write to either a frame or a newly opened window, such as the

following:

Remember that both

write()

and

writeln()

must be called before the page has

been fully loaded in order to insert the content properly. If either method is called

after the page is loaded, it erases the page and displays the content specified.

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