separate php snippets do not connect

[php]
add_action( 'admin_footer', 'my_action_javascript' );

function my_action_javascript() {
[/php]
//some js code
[php]
}
[/php]

This code produces “syntax error, unexpected end of file”.
Any tips please?

https://ww.wp.xz.cn/plugins/allow-php-in-posts-and-pages/