One of the most usual ways you will use VBScript is to display text, as if
you were using HTML.
Indeed, added just a few instructions, you can use
any of the HTML tags and make them part of your script. Therefore,
everything you have learned in HTML is valid here.
To set the instructions of a script from the HTML
tags, the section that has the script must start with the <SCRIPT>
tag and end with the </SCRIPT> tag, as follows:
<SCRIPT>
</SCRIPT>
You can write the tag in all uppercase, all lowercase,
or a mix
Because a script is written in a particular language
that is not HTML, and because there are various scripting languages in the
industry, to use a script, you should let the browser know what (particular)
scripting language you are using. To let the browser know, inside of the
<SCRIPT> tag, type the word Language, followed by the
= sign, followed by the name of the script language
included in double-quotes. For example, to use a VBScript in a page, start
the section with <Script language="VBScript"> and end it
with the closing tag. Therefore the scripting section can be delimited
with:
<Script Language="VBScript>
</Script>
Like HTML, VBScript is not case sensitive. This means
that script, SCRIPT, script, and Script are the same.
Therefore, you can also include a script in the following:
<SCRIPT LANGUAGE="VBScript">
</SCRIPT>
The section between the opening <Script> tag and
the closing </Script> tag is called the body of the script.
Everything that is part of the body of a script belongs to the script.
VBScript uses an object called Document. This object manages many
of the instructions that VBScript can handle for HTML. One of the
functions of that object is to display a string on the screen. A string is
text that the browser is asked to use "as is".
The function used is called Write. The syntax of the Write function of the
Document object is:
Document.Write(String)
The String to display can be provided in
double-quotes or as a variable as we will learn soon. Here is an example of
displaying somebody's name using the Document.Write() function:
To display various lines of text, you can use as many
Document.Write() lines as you need.
A file can have many different script sections and you can include as many lines of code as necessary in a file. To
have different script sections, start each with the <SCRIPT> tag and
close it with the closing tag. Here is an example:
|
<SCRIPT LANGUAGE="VBScript">
Document.Write("Book Title: ")
Document.Write("VBScript Programming")
</SCRIPT>
<SCRIPT LANGUAGE="VBScript">
Document.Write("Author: Martin Russel Bitha")
Document.Write("Publisher: Les moules Press")
Document.Write("Year Published: 1998")
</SCRIPT>
|
 Practical Learning: Introduction to VBScript |
|
|
VBScript and HTML Tags
|
|
Everything you learned in HTML is readily available in VBScript. VBScript allows you
to mix its own syntax with HTML tags. In order to use this more
efficiently, you should understand the mechanics of VBScript.
When
you include a string in your VBScript and send it to Internet Explorer,
everything that is part of the string is sent to the browser "as
is". Once the browser receives your string from the Document.Write()
function, it gets rid of the Document.Write words, the parentheses and
double-quotes. Then it treats the rest, the part of the string, as HTML
code. If the string that was sent is just a group of characters, the browser would
display its text. If you send any special character, the browser would
analyze it to find out if the character is a special HTML symbol. If it
is, it would be treated appropriately. For this reason, a script can
result in complex code or difficult to interpret errors.
Based
on this, you can include any HTML tag as part of the string. Here is an
example:
When the browser receives this script,
it gets rid of everything that is not part of the string. After this
operation, the remaining text becomes:
This is what the browser would try to display. As it
happens, there is an HTML tag in the code, namely the break tag <br>;
therefore, the break tag would be applied.
You can include any HTML tag as part of
your script. Make sure you use the HTML tags appropriately; VBScript will
not correct or interpret your tags, it would send them to the browser as they are
written.
|
|
Practical Learning: Including HTML Tags in a Script
|
- Change the file as follows:
<Script Language="VBScript"> Document.Write("Leaving Sydney<br>") Document.Write("When we decided to leave, we knew we were ") Document.Write("making a hard decision. We had spent so much ") Document.Write("time this had become our new home. A few weeks ") Document.Write("or months before, we wanted to make Sydney ") Document.Write("our newly found settlement, a permanent place ") Document.Write("we could proudly call ours. It appeared that, ") Document.Write("unpredictably, fate had decided otherwise.") </Script> - Save the file and preview the page in your browser
- After previewing the page, return to Notepad
- To make the page more attractive, change it as follows:
<Script Language="VBScript"> Document.Write("<h1><font face=Verdana color=red>Leaving Sydney</font></h1>") Document.Write("<p>When we decided to leave, we knew we were ") Document.Write("making a hard decision. We had spent so much ") Document.Write("time this had become our new home. A few weeks ") Document.Write("or months before, we wanted to make <b>Sydney</b> ") Document.Write("our newly found settlement, a permanent place ") Document.Write("we could proudly call ours. It appeared that, ") Document.Write("<i>unpredictably</i>, fate had decided otherwise.</p>") </Script> - Save the file. Return to browser and refresh it
- To use more tags, for example to create a table in your script,
change the file as follows:
<Script Language="VBScript"> Document.Write("<table border=0 width=550>") Document.Write(" <tr>") Document.Write(" <td width=100% align=center>") Document.Write("<font face="Garamond, Times New Roman, Georgia" size=6 color="#FF0000">") Document.Write("<b>Leaving Sydney</b>") Document.Write("</font>") Document.Write(" </td>") Document.Write(" </tr>") Document.Write("</table>") Document.Write("<table border=0 width=550>") Document.Write(" <tr>") Document.Write(" <td width=100%>") Document.Write("<p>When we decided to leave, we knew we were ") Document.Write("making a hard decision. We had spent so much ") Document.Write("time this had become our new home. A few weeks ") Document.Write("or months before, we wanted to make <b>Sydney</b> ") Document.Write("our newly found settlement, a permanent place ") Document.Write("we could proudly call ours. It appeared that, ") Document.Write("<i>unpredictably</i>, fate had decided otherwise.</p>") Document.Write("<hr color=#FF9933>") Document.Write(" </td>") Document.Write(" </tr>") Document.Write(" <tr>") Document.Write(" <td width=100% align=right>") Document.Write("Author: Arthur D. Pale<br>") Document.Write("Title: Stories Of My Life") Document.Write(" </td>") Document.Write(" </tr>") Document.Write("</table>") </Script> - Save the file and check it in the browser
- After previewing the page, return to Notepad and close it.
|
Techniques of Managing Code
|
|
HTML Comments
|
|
In some cases, when an older browser interprets your
code, it may not be able to validate it. To hide your code from an older
browser, include it between <!-- and -->.
A comment is a line of code that is not examined, read, or
interpreted by the browser. This means that the browser doesn't display
anything that is part of a comment. Therefore, a comment can be written in plain
English or the language you are using, with words aligned however you want them.
To add a comment to your HTML code, you can include it between <!-- and
-->.
|
|
VBScript Comments
|
|
There are two ways you can write a line of comment in
VBScript. To create a comment, start the section with the keyword Rem.
Everything on the right side of Rem is part of the comment. Here is an
example:
|
<SCRIPT LANGUAGE="VBScript">
Rem This line is ignored. I can write it however I want.
Document.Write("2006 FIFA World Cup")
</SCRIPT>
|
|
Using the Rem keyword, you can add as many lines of comments as you want. A comment
doesn't have to stand on its own line. It can be part of a line of code as long as
it starts with Rem and the Rem keyword is not part of code. To add a comment to a
line that contains code already, type Rem and include your comment. Once again,
anything on the right side of Rem would be ignored by the browser. Here is an
example:
|
<SCRIPT LANGUAGE="VBScript">
Rem This line is ignored. I can write it however I want. Document.Write("2002 FIFA World Cup")
Rem The 2002 World Cup was in Rep Korea and Japan </SCRIPT> |
|
Besides using the Rem keyword, another technique for commenting is by using the
single quote character. The single quote plays the exact same role as the Rem
keyword. Because of its briefness, the single quote is preferred and is more
popular than the Rem keyword.
To create a comment, type the single quote character followed
by the desired text of comment. Here is an example:
|
<SCRIPT LANGUAGE="VBScript">
' Anything on this side is part of a comment
Document.Write("They scored two soft goals")
</SCRIPT>
|
|
You can use the single quote the same way you would use the
Rem keyword. To add
a comment on a line that already has code, type ' followed by the desired text.
You can also use a mix of Rem and single quote comments in the same script.
Here is an example:
|
<SCRIPT LANGUAGE="VBScript">
' Movie Quote
Document.Write("<p>We went through a lot of trouble because of you.<br>")
Document.Write("You owe us.</p>") Rem Max starts having a stroke here
Rem Display the movie title
Document.Write("<b>Title:</b> Disorganized Crime")
</SCRIPT>
|
|
Practical Learning: Using Comments to VBScript Code |
- To add Rem comments to your code, change the file as follows:
<Script Language="VBScript"> Rem This exercise illustrates the use of HTML tags inserted into VBScript code Rem This is how to add a simple table made of one row and one column Document.Write("<table border=0 width=550>") Document.Write(" <tr>") Document.Write(" <td width=100% align=center>") Document.Write("<font face="Garamond, Times New Roman, Georgia" size=6 color="#FF0000">") Document.Write("<b>Leaving Sydney</b>") Document.Write("</font>") Document.Write(" </td>") Document.Write(" </tr>") Document.Write("</table>") Rem This is another example of a table Document.Write("<table border=0 width=550>") Document.Write(" <tr>") Document.Write(" <td width=100%>") Document.Write("<p>When we decided to leave, we knew we were ") Document.Write("making a hard decision. We had spent so much ") Document.Write("time this had become our new home. A few weeks ") Document.Write("or months before, we wanted to make <b>Sydney</b> ") Document.Write("our newly found settlement, a permanent place ") Document.Write("we could proudly call ours. It appeared that, ") Document.Write("<i>unpredictably</i>, fate had decided otherwise.</p>") Document.Write("<hr color=#FF9933>") Document.Write(" </td>") Document.Write(" </tr>") Document.Write(" <tr>") Document.Write(" <td width=100% align=right>") Document.Write("Author: Arthur D. Pale<br>") Document.Write("Title: Stories Of My Life") Document.Write(" </td>") Document.Write(" </tr>") Document.Write("</table>") </Script> - Save the sydney.htm file and preview the web page in your browser
- Notice that the page still displays the same way.
After previewing the page, return to Notepad - To use a mix of Rem and single quote comments, change the file as
follows:
<Script Language="VBScript"> Rem This exercise illustrates the use of HTML tags inserted into VBScript code Rem This is how to add a simple table made of one row and one column Document.Write("<table border=0 width=550>") Document.Write(" <tr>") Document.Write(" <td width=100% align=center>") Document.Write("<font face="Garamond, Times New Roman, Georgia" size=6 color="#FF0000">") Document.Write("<b>Leaving Sydney</b>") Document.Write("</font>") Document.Write(" </td>") Document.Write(" </tr>") Document.Write("</table>") Rem This is another example of a table ' This time, the table is made of two rows and one column Document.Write("<table border=0 width=550>") Document.Write(" <tr>") Document.Write(" <td width=100%>") ' This paragraph displays in the top cell Document.Write("<p>When we decided to leave, we knew we were ") Document.Write("making a hard decision. We had spent so much ") Document.Write("time this had become our new home. A few weeks ") Document.Write("or months before, we wanted to make <b>Sydney</b> ") Document.Write("our newly found settlement, a permanent place ") Document.Write("we could proudly call ours. It appeared that, ") Document.Write("<i>unpredictably</i>, fate had decided otherwise.</p>") Document.Write("<hr color=#FF9933>") Document.Write(" </td>") Document.Write(" </tr>") Document.Write(" <tr>") Document.Write(" <td width=100% align=right>") Document.Write("Author: Arthur D. Pale<br>") Document.Write("Title: Stories Of My Life") Document.Write(" </td>") Document.Write(" </tr>") Document.Write("</table>") </Script> - Save and preview the file, then return to Notepad
|
Code Indentation
|
|
Code confined and heavily written can be hard to read. This will become
even more difficult when we start adding variables, functions, and
conditional statements. One remedy to making the code easier to read is to
indent its sections. Although most (commercial) code editors assist
programmers with code indentation, in Notepad, you will indent your code
the way you want.
Indentation is similar to adding empty characters to a
line of text by pressing Tab when starting a line of code. It can also be
performed by press the Space bar at the beginning of a line of code. This leaves an empty space
or empty spaces on the left side of the line being
indented. Because indentation is not part of your code, it is a matter of
choice and taste. One of the most common techniques is to indent a section
by two or four empty characters from the previous section. To do this, in
Notepad, press the Space bar two or four times and add your code. Here is
an example:
|
<SCRIPT LANGUAGE="VBScript">
Document.Write("<p>We went through a lot of trouble because of you.</p>")
</SCRIPT>
|
|
As you can see from the previous code, indentation of the
Document.Write()
calling allows you to know where the <SCRIPT> tag starts. Therefore,
you will be able to know where a piece of code, such as the <SCRIPT>
tag, must be closed.
Since your code will usually be made of different
sections, a particular section of code should have the same level of
indentation. Once again, this makes your code easier to read and navigate:
|
<SCRIPT LANGUAGE="VBScript">
' Movie Quote
Document.Write("<p>We went through a lot of trouble because of you.<br>")
Document.Write("You owe us.</p>") Rem Max starts having a stroke here
Rem Display the movie title
Document.Write("<b>Title:</b> Disorganized Crime")
</Script>
|
|
Practical Learning: Indenting Code |
- To add indentation to your code, change the file as follows:
<Script Language="VBScript"> Rem This exercise illustrates the use of HTML tags inserted into VBScript code Rem This is how to add a simple table made of one row and one column Document.Write("<table border=0 width=550>") Document.Write(" <tr>") Document.Write(" <td width=100% align=center>") Document.Write("<font face="Garamond, Times New Roman, Georgia" size=6 color="#FF0000">") Document.Write("<b>Leaving Sydney</b>") Document.Write("</font>") Document.Write(" </td>") Document.Write(" </tr>") Document.Write("</table>") Rem This is another example of a table ' This time, the table is made of two rows and one column Document.Write("<table border=0 width=550>") Document.Write(" <tr>") Document.Write(" <td width=100%>") ' This paragraph displays in the top cell Document.Write("<p>When we decided to leave, we knew we were ") Document.Write("making a hard decision. We had spent so much ") Document.Write("time this had become our new home. A few weeks ") Document.Write("or months before, we wanted to make <b>Sydney</b> ") Document.Write("our newly found settlement, a permanent place ") Document.Write("we could proudly call ours. It appeared that, ") Document.Write("<i>unpredictably</i>, fate had decided otherwise.</p>") Document.Write("<hr color=#FF9933>") Document.Write(" </td>") Document.Write(" </tr>") Document.Write(" <tr>") Document.Write(" <td width=100% align=right>") Document.Write("Author: Arthur D. Pale<br>") Document.Write("Title: Stories Of My Life") Document.Write(" </td>") Document.Write(" </tr>") Document.Write("</table>") </Script> - Save and preview the file, then return to Notepad
No comments:
Post a Comment