PHP program to demonstrate the NULL reference exception using exception handling

Program/Source Code:

The source code to demonstrate the NULL reference exception using exception handling is given below. The given program is compiled and executed successfully.

<?php
//PHP program to demonstrate the NULL reference exception
//using exception handling.
class Sample
{
    public function PrintHello()
    {
        printf("Hello World<br>");
    }
}

function GetObject()
{
    $obj = new Sample();
    return $Obj;
}
try
{
    $obj = GetObject();

    if ($obj == null) throw new Exception("Null reference exception");

    $obj->PrintHello();
}
catch(Exception $e)
{
    printf("Exception: %s", $e->getMessage());
}
?>

Output:

Exception: Null reference exception

Explanation:

Here, we created used try and catch block. In the try block we created a class Sample that contains a method PrintHello(), which is used to print "Hello World" on the webpage.

Here, we created a function GetObject(), which is used to return the object of Sample class, here we created object $obj of Sample class but we return $Obj. That's why it will return a null value.

if($obj==null)
    throw new Exception("Null reference exception");

Here, we check the value of $obj, if it contains a null value then Exception will be thrown an caught by the catch block and print the specified exception message on the webpage.