defining constant in php

[wolf73]

Hi, I see the following statement in php manual

Constants may only be defined using the define() function, not by simple assignment;

But I try the following code it works
<?php
$test= "abcd";
echo "$test";
?>

 

[rhyno2k]

Wolf,

In your example, $test is a variable, not a constant.

Constants are defined as such:

define('TEST', "abcd");

The names of each describe their use.

Constants are... constant. You can't change them.
Variables are... variable. You can change them at any time.

 

[wolf73]

Thanks a lot ..

 

[jpadie]

there is also a difference in scope and assignment.

1. you cannot assign a constant to the output of a function.

2. (to my mind most importantly) a constant is in the global scope.