<?php
class test{
  public $x=1;
  public $setting;
  //負責生成其他對象的類或方法,這就是工廠模式
  public function getSetting(){
    if(!$this->setting){
      $this->setting=new Setting();
    }
    return $this->setting;
  }
}
class Setting{
  public function __construct(){
    echo 1111;
  }
}
$test=new test();
$setting=$test->getSetting();
$setting2=$test->getSetting();
 
 
//判斷兩個對象是否是同一個對象
var_dump($setting===$setting2);
//看編號,也能看出來
var_dump($setting);
var_dump($setting2);
 
 
 
 
//屬性中有減號的處理
$name="x-b";
$test->$name=2;
 
var_dump($test);
 
 
//$test->x-b;//直接使用上面的屬性,會被認為是一個減號
/*
報錯:
PHP Notice: Use of undefined constant b - assumed 'b' in D:\phpServer\WWW\test\
test.php on line 11
 
Notice: Use of undefined constant b - assumed 'b' in D:\phpServer\WWW\test\test.
php on line 11
 
*/
 
echo $test->{'x-b'}; //這種屬性里面有-的這樣包一下