php if query works with wamp but not on live server

Question

I'm using the code below to choose an image based on the domain.

the only difference between environments is wamp is running PHP 7 and my host 7.1 and I've been unable to get a copy of wamp with PHP 7.1 included.

on the live site, the end result is a blank white page with the PHP error on the 'else' line

I'm not sure if this is correct but after $logo_img = "3_logo.svg" if I add the semicolon you get a white page but without works just fine.

<?php
                    $host = $_SERVER['HTTP_HOST']; 
                    $logo_img = '';

                    if($host == "1.co.uk") {
                        $logo_img = "1_logo.svg"; 
                    }
                    else if($host == "2.co.uk") {
                        $logo_img = "2_logo.svg"; 
                    }
                    else($host == "3.co.uk") {
                        $logo_img = "3_logo.svg" //with semicolon errors - unexpected ';'
                    }



                    ?>

any help appreciated!!

UPDATE:

var_dump ($_SERVER['HTTP_HOST']); returns

Localhost

string 'localhost' (length=9)

Live site

string(23) "www.domain.co.uk"

Answer 1

Please fix this here is syntax error

else($host == "3.co.uk") {
                        $logo_img = "3_logo.svg" //with semicolon errors - unexpected ';'
                    }

you need to write

elseif($host == "3.co.uk") {
                        $logo_img = "3_logo.svg";
                    }
else{ ..... }