无法理解为什么我收到未定义的索引错误

Question

Hi i am getting an error Undefined index: HTTP_HOST on this line can any of you tell me where i am going wrong

define("SCH_WSLINK", "{$httpS}://{$_SERVER['HTTP_HOST']}");

cheers

Answer 1

is $httpS defined?

$httpS = 'https';
define("SCH_WSLINK", "{$httpS}://{$_SERVER['HTTP_HOST']}");

The above code works for me...

var_dump(SCH_WSLINK);
string(16) "https://test.loc"

Answer 2

the cause of your error is that $httpS is interpreted as a variable which is not defined ,this will work :

<?php
    define("SCH_WSLINK", "{\$httpS}://{$_SERVER['HTTP_HOST']}");
    echo SCH_WSLINK;
?>