Class: Explained : Always Simple


The example below is a simple class with one constructor function; here class name and function name are same as "A".
  • Keyword : class and curly braces {  }
  • Benefit : ruse, encapsulation and inheritance
  • No Pointer like C++
 
<?php
class A {
public function A($param) {
echo "Constructing A.$param<br>";
}
}
//calling classes, creating instances
$a = new A(10);
?>

 
 
When you create an object by using a new instance of  the class ( that is an object). The example shown below, passes a variable/parameter from a "Form" to an argument of function "anyfunction". The symbol "->" in the code "$some_object->anyfunction($y);" , works like a pointer and it can be used
Code: pointer_to_variable.php

<?php
class myClass {

var $word = 'Hello Wrold';

function myClass(){ echo "Constructor <br>";
}
function something($n) { echo "<br> Received : $n "; }
}
$some_object=new myClass();
echo $some_object->word;
echo "<br>sending parameter 10 to function something ";
echo $some_object->something(10);
?>
 
Pointer to variables are not efficient, and looked like they are loosely attached
 code:class_explined.php

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<title>class_explained</title>
</head>
<body text="#FFFF00" bgcolor="#000080">
<?php
$y=$_POST['T1'];
class myClass {
var $word ='welcome';
function myClass(){
echo "An instance is created, I am a constructor <br>";
}
function anyfunction($x){
echo "This function was called me as <font color='#FF0000'> $x </font>";
}
}
$mine=new myClass();
echo "<br>Calling a variable with <br>";
echo $mine->$word ;
$mine->anyfunction($y);

?>
<form method="POST" action="class_explained.php">
<p><input type="text" name="T1" size="20"><br>
<input type="submit" value="Submit" name="B1">
<input type="reset" value="Reset" name="B2"></p>
</form>
</body>
</html>