Properties in PHP Classes: Defining Data Fields

• Class member variables are called properties. Sometimes they are referred as attributes or fields.
• The properties hold specific data and related with the class in which it has been defined.
• Declaring a property in a class is an easy task, use one of the keyword public, protected, or private followed by a normal variable declaration. If declared using var (compatibility with PHP 4), the property will be defined as public.
  
  • public : The property can be accessed from outside the class, either by the script or from another class
  • private : No access is granted from outside the class, either by the script or from another class.
  • protected : No access is granted from outside the class except a class that’s a child of the class with the protected property or method.

Example:

After an object is instantiated, you can access the property of a class using the object and -> operator. Any member declared with keyword "private" or "protected" cannot be accessed outside the method of the class.

Syntax

<?php   
class Myclass
{
 public $font_size =10;
}
$f = new MyClass;
echo $f->font_size;
?>

Output

10

Note: There is a common mistake to use more than one dollar sign when accessing variables. In the above example there will be no $ sign before font_size (echo $f->font_size).

Another Example

Syntax

<?php
class Dress{  
	public $color = "red";  // The color of the dress 
	Public $fabric = "linen"; // The fabric of the dress 
	Public $design = "Slim Fit Blazer";//The design of the dress   

}

$dressObj = new Dress();
$dressObj->color = "Black";

var_dump($dressObj); 
echo "</br></br>";
print_r($dressObj); 
?>