PHP全局变量教程

---

$_GLOBALS

$_GLOBALS打印出所有的全局变量，当做索引存储在$_GLOBALS里面，

比方说你有全局变量$theme_fields, 那这形式就是 $_GLOBALS【‘theme_fields’】，

相当于 先申明 global $theme_fields ， 然后设置$theme_fields.

WP自带的全局变量

1:SIte globals

2:Admin globals

3:Browser detection globals

4:Web server detection globals

5:Version variable globals

Browser Detection globals

is_iphone, is_chrome, is_safari, is_opera, is_macIE，is_edge 等。

global $is_chrome; 
if ($is_chrome) {
  # code...

  echo "You are useing chrome";
} 
if ($is_edge) {
  # code...
  echo "You are using edge";
}

firefox的话 是 $is_gecko

Web server / version detection

if ($is_apache) {
  # code...
  echo "<h2>You are useing apache</h2>"; 
} else {
  echo "SYSTME has no server";
}

Version

$wp_version, $wp_db_version, $tinymce_version, $mnifest_version, $required_php_version, $required_mysql_version

$wpdb,$wp_locale,$wp_roles,$wp_registered_sidebars

---