Very cool! Thanks! "Christopher Raymond" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Shawn: > > I beleive I can clarify the purpose of objects/classes for you and > enrich my clarification with a couple of examples. > > > THE DIFFERENCE BETWEEN "OBJECT" AND "CLASS": > > A class defines the structure of an object. A class is a "template" > for an object. An object is a container for data and for functions that > operate on that data. A class is a roadmap -- it defines the object's > structure. You can then create several objects using one class. These > several objects are separate from one another, but identical in > structure. Each can contain different data but use the same functions to > operate on that data. > > Functions contained within an object class are called methods. > Functionally, methods are exactly the same as functions except that they > are restricted to the scope of the object. Generally, a method is a > function that operates on the object's data. An object contains variable > data including variables, arrays and objects. These variables are called > the object's properties. > > > WHEN TO USE OBJECTS: > > Objects could be used when you have several similar pieces of data > especially when you wish to have that data manipulated by the same > functions but wish to maintain separation between these data objects. > > > EXAMPLE: > > Let's say, for example, that you wished to store information about a > number of different people within a single script execution. An > insurance site might wish to gather information about the primary > applicant, his wife and their three children all on the same page. > > You and I would agree that all people have similar properties; we all > have an age, a height, a weight - we might smoke etc. Therefore, a class > for people could be defined. > > class Human > { > var $age; > var $height_inches; > var $weight_pounds; > var $smoker; > > function HeightWeightRatio() > { > $ratio = $this->height_inches / $this->weight_pounds; > return $ratio; > } } > } } > > To create an instances of the class (an object) you would use > something like this: > > $father = new Human; > $mother = new Human; > > Once you have instantiated the class (previous lines) you could then > set the values of the object with code like: > > $father->age = 49; > $father->height = "5'11"; > $father->weight = 215; > $father->smoker = false; > > $father_ratio = $father->HeightWeightRatio(); > > $mother->age = 47; > $mother->height = "5'5"; > $mother->weight = 145; > $mother->smoker = true; > > $mother_ratio = $mother->HeightWeightRatio(); > > By now, I'm sure you get the picture. > > > THE MOST USEFUL EXAMPLE FOR ME THUS FAR: > > class HTMLTemplate > { > > var $template; > var $html; > var $parameters > = array(); > var $populated = false; > > function HTMLTemplate ( > $template) > { > > $this->template = $template; > $this->html = > implode ("", (file($this->template))); > > } > > function SetParameter ( > $variable, $value) > { > > $this->parameters[$variable] = $value; > > } > > > function PopulateValues () > { > > foreach ($this->parameters as > $key => $value) > { > > $template_name = '<!--{' . $key . '}-- > >'; > $this->html = str_replace ($template_name, $value, $this->html); > } > > > $this->populated = true; > } > > function ReturnHTML () > { > if ( > $this->populated) > { > return $this->html; > } > else > { > > $this->PopulateValues(); > return $this->html; > } > } > } > > This class allows you to use an html template file which you can paste > dynamic values/content into. Here's an example of how to use it: > > <?php > > $title = "My Web Page"; > $content = "Hello, this is my web page."; > > $template = new HTMLTemplate("/mytemplate.html"); > $template->setParameter("PAGE-TITLE", $title); > $template->setParameter("CONTENT", $content); > > echo $template->ReturnHTML(); // Sends html to the browser > > // It is important to destroy an object once you are finished > // using it so that you can free up the memory space that it uses > > unset($template); // Destroys instance of object > > ?> > > HTML TEMPLATE FILE: > > My html template file might look like this: > > <html> > <head> > <title><!--{PAGE-TITLE}--></title> > </head> > <body> > <!--{CONTENT}--> > </body> > </html> > > > Christopher Raymond, > Oasis Networks <-- Web Development & Macintosh Systems Consulting
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