gistfile1.php

<?php
  /**
    * Function vs constant test
    *
    * Constant should be faster with the interpreter, but maybe the compiler inlines the function?
    *
    */
    
  class Test{
    var $runs = 10000000;
  
    const constant = 'IAMCONST';
    function func(){ return 'IAMFUNC';}
    
    public function testfunction(){
      $start = microtime(true);
      
      for($i=0; $i<$this->runs; $i++){
        $a = $this->func();
      }
      
      return microtime(true) - $start;
    }
    
    public function testconst(){
      $start = microtime(true);
      
      for($i=0;$i<$this->runs; $i++){
        $a = self::constant;
      }
      
      return microtime(true) - $start;
    }
  }

  
  $test = new Test();
  
  print_r(array("Constant" => $test->testconst()));
  print_r(array("Function" => $test->testfunction()));
  
  exit("EXIT");
?>