PHP，JavaScript 获取当前域名、判断网址协议是否为 HTTPS

/** 
* 判断当前协议是否为 HTTPS 
*/ 
function is_https() 
{ 
if ( !empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off') { 
return true; 
} elseif ( isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https' ) { 
return true; 
} elseif ( !empty($_SERVER['HTTP_FRONT_END_HTTPS']) && strtolower($_SERVER['HTTP_FRONT_END_HTTPS']) !== 'off') { 
return true; 
} 
return false; 
} 

echo domain();//https://www.itqaq.com 
/** 
* 获取包含网址协议的域名 
*/ 
function domain() 
{ 
$http_type = ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') || (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https')) ? 'https' : 'http'; 
return $http_type . '://' . $_SERVER['HTTP_HOST']; 
} 

function is_https() 
{ 
return 'https:' == location.protocol ? true: false; 
} 

var domain = location.protocol + '//' + location.host