how to auto redirect http to https code example

Example 1: htaccess redirect to https

RewriteEngine On
RewriteBase /
RewriteCond %{HTTPS} !=on
RewriteCond %{HTTP_HOST} ^yourdomain\.com [OR]
RewriteCond %{HTTP_HOST} ^www\.yourdomain\.com
RewriteRule .* https://yourdomain.com%{REQUEST_URI} [R=301,L]

Example 2: redirect htaccess http to https

RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://www.yourdomain.com/$1 [R,L]

Example 3: how to automatically redirect to https

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

Example 4: redirect https

if ($_SERVER['HTTPS'] != "on") 
{
    $url = "https://". $_SERVER['SERVER_NAME'] . $_SERVER['REQUEST_URI'];
    header("Location: $url");
    exit;
}