Is PHP function names case-sensitive or not? [closed]

Question

I am from Java background. In Java, every method has case-sensitive while calling. But in PHP, I didn't see the case-sensitive function name while calling the functions.

class Sample {

    ...
    ...

    function sampleFunction() {

       ....
       ....

    }

}

$obj = new Sample();
$obj->sampleFunction(); /* Proper call with function name */
$obj->samplefunction(); /* It should show undefined function error but it also calls sampleFunction()  */

Can anyone clear my doubt why this is also called even non-case sensitive function name. And please give me how to restrict in PHP?

Thanks in advance.

Answer 1

They are case insensitive, see this:

Note: Function names are case-insensitive, though it is usually good form to call functions as they appear in their declaration.

http://www.php.net/manual/en/functions.user-defined.php

Answer 2

Functions are not case sensitive, Variables are case sensitive.

you can read more info from manual :

http://fr.php.net/manual/en/functions.user-defined.php