<?php
class books {
//public
public $title = array();
public $image = array();
public $author = array();
public $description = array();
public $year = array ();
public $price = array();
// private
private $filename = "data.txt";
//class constructor
function __construct()
{
$i=-1;
$lines = file($this->filename);
foreach ( $lines as $line) {
if (strlen($line) > 2) {
$line = rtrim($line);
list($what, $content) = explode("=> ", $line);
if ($what == "Title") {
$i++;
$this->title[$i]=$content;
}
elseif ($what == "Image") {
$this->image[$i]=$content;
}
elseif ($what == "Author") {
$this->author[$i]=$content;
}
elseif ($what == "Description") {
$this->description[$i]=$content;
}
elseif ($what == "Year") {
$this->year[$i]=$content;
}
elseif ($what == "Price") {
$this->price[$i]=$content;
};
};
};
} // end constructor
} // end GetData
as i know,in class, i can declare function optionally.but why i shoud declare a function like this"function __constructor(){ }".don’t know when i should declare constructors in a class and what’s the role it plays in a class. thank you.
