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Script functions can be declared with parameters , which are passed to the function when it is called.
Parameters are declared by naming them in the <A NAME>
declaration tag, after the NAME attribute and any scope
attribute (PUBLIC/PRIVATE etc.) . Each parameter is a
local variable (here) inside the function:
<A NAME=banner title="Untitled" bg>
<HEAD>
<TITLE>$title</TITLE>
</HEAD>
<BODY BGCOLOR=$bg>
<CENTER>
<H2>$title</H2>
</CENTER>
</A>
This function has two parameters, $title and $bg.
When the function is called, its arguments are named in the tag (like
HTML attributes):
<banner title="Search Results" bg=white>
Since the arguments are named, they need not be given in order (like HTML). Nor are all
parameters required: the $title parameter was declared with a
default value of "Untitled", so it will have that value if
unspecified in a call:
<banner bg=white>
Parameters without default values (e.g. $bg) are
required, however. This provides the ability to force their setting
in situations where a default value might not be useful. For example,
a search-and-replace type function could require its search and buffer
parameters: it may not be sensible to search a default buffer.
The default value for a parameter can also be a variable:
<A NAME=banner title=$DefaultTitle bg>
...
</A>
In this case, if $title is not specified in a call, it will
have the value of the global (never local) variable $DefaultTitle.
Copyright © Thunderstone Software Last updated: Mon Feb 18 10:28:15 EST 2013
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