php基础_常量

<?php

/* 
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

// refer to document: http://www.php.net/manual/zh/language.constants.php
// http://www.php.net/manual/zh/language.constants.predefined.php

//int 
define('VERSION0',(int)1);
var_dump(VERSION0);

//float
define('VERSION1',(float)1);
var_dump(VERSION1);

//string
define('VERSION2',(string)1);
var_dump(VERSION2);

//Bool
define('VERSION3',TRUE);
var_dump(VERSION3);

//null
define('VERSION4',NULL);
var_dump(VERSION4);

//array  is error
define('VERSION5',(array)1);
var_dump(VERSION5);

//object   is error.
define('VERSION6',(object)1);
var_dump(VERSION6);