/usr/share/doc/sludge/SLUDGEDevKitHelp/Variables.html

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<TITLE>Variables</TITLE>
  <link rel="stylesheet" type="text/css" href="style.css" />
</head>
<BODY>
<HR>
<div align="center"><img id="headerGraphic" src="images/sludge300.png" alt="SLUDGE"/></div>
<h2>Variables</h2>
<HR>


<P>
SLUDGE has only one variable structure - the &quot;var&quot; - which can hold many different types of data. The different data types which can be held in a SLUDGE variable are:
</P>

<P>
<B>Undefined:</B>
</P>

<P>
Not much use, but it's the value to which variables are initialised, and the default return value from user defined functions.
</P>

<P>
<B>Numbers:</B>
</P>

<P>
For those of you who know C or C++, they're long signed integers. For everyone else, they're big but they can't do decimal points. Whoever heard of an adventure game saying &quot;It's a bag of 482.66666666667 gold coins&quot;?
</P>

<P>
<B>Strings:</B>
</P>

<P>
Used for holding text. All of the other data types can be turned into strings automatically, making debugging a lot simpler - see the <a href="Treating_Variables_as_Strings.html">Treating Variables as Strings</a> page.
</P>

<P>
<B>File handles:</B>
</P>

<P>
How do you get a picture, sound, sprite bank or floor into your code? Here's how. Read up on these in the <a href="File_Handling.html">File Handling</a> section.
</P>

<P>
<B>Object types:</B>
</P>

<P>
Objects, actions and characters. More information on creating and using these is available in the <a href="Object_Types_and_Events.html">Object Types and Events</a> section.
</P>

<P>
<B>Stacks:</B>
</P>

<P>
These double as arrays, but you don't have to set any boundaries. Stacks can hold any number (including 0) of other variables of any - or mixed - data types. And yes, that includes other stacks. See the section about <a href="The_Multi-Purpose_Stack___Array___Queue_Type.html">The Multi-Purpose Stack / Array / Queue Type</a> for more information.
</P>

<P>
<B>Function handles:</B>
</P>

<P>
Pass a function around like a variable! Fun, fun, fun. There's <a href="Passing_Functions_as_Variables.html">more information here</a>.
</P>

<P>
<B>Animations:</B>
</P>

<P>
Created using the <a href="anim.html">anim</a> function.
</P>

<P>
<B>Costumes:</B>
</P>

<P>
Created using the <a href="costume.html">costume</a> function.
</P>


<H3>Local and global variables:</H3>

<P>
Variables can be local or global. Local variables (defined inside a function) exist for only the duration of the <a href="Functions_(subs).html">function</a> in which they are defined; global variables (defined outside of all the functions) are accessible to everything. For example:
</P>

<P>
<pre>var thisIsGlobal = 5;

sub someFunction () {
   var thisIsLocal = 10;
   say (ego, thisIsGlobal + thisIsLocal);
   # Fine
}

sub someOtherFunction () {
   say (ego, thisIsGlobal + thisIsLocal);
   # Not fine... in this function we have no idea what &quot;thisIsLocal&quot; is
}</pre>
</P>

<H3>More on this subject:</H3>

<P>
<a href="Treating_Variables_as_Booleans.html">Treating Variables as Booleans</a>
</P>

<P>
<a href="Treating_Variables_as_Strings.html">Treating Variables as Strings</a>
</P>

<P>
<a href="The_Multi-Purpose_Stack___Array___Queue_Type.html">The Multi-Purpose Stack / Array / Queue Type</a>
</P>

<P>
<a href="Variable_Operations.html">Variable Operations</a>
</P>

<P class="copyright-notice">SLUDGE and this SLUDGE documentation are <A HREF="Copyright.html">copyright</A> Hungry Software and contributors 2000-2012
</P>

<HR>
</BODY>
</html>
sludge-doc 2.2-1 / usr / share / doc / sludge / SLUDGEDevKitHelp / Variables.html
