PHP/Math/define

Constants and switch statement

 
<?php 
define("ALIGN_LEFT", 1); 
define("ALIGN_CENTER", 2); 
define("ALIGN_RIGHT", 3); 

switch($value) { 
    case ALIGN_LEFT : 
        break; 
    case ALIGN_CENTER : 
        break; 
    case ALIGN_RIGHT : 
        break; 
} 
?>

Constants, like the names of variables, are case-sensitivebut unlike variables

 
They do not start with a dollar sign. 
You can change this behavior by passing true as a third parameter to define( ), which makes the constant case-insensitive:
<?
    define("SecondsPerDay", 86400, true);
    print SecondsPerDay;
    print SECONDSperDAY;
?>

Define a constant as an array or object

 
<?php 
$arr = array("apple", "orange", "pear"); 
define("MYARRAY", serialize($arr)); 
function MyTest() { 
    print_r(unserialize(MYARRAY)); 
} 
MyTest(); 
?>