PHP

php variable constant

if (...) {
     const FOO = 'BAR';    // Invalid
 }
 // but
 if (...) {
     define('FOO', 'BAR'); // Valid
 }

php get constant value

define("MAXSIZE", 100); //set the value

echo MAXSIZE; //to get the value
echo constant("MAXSIZE"); //to get the same value