MODX revo – If statements for check if is page with id…

I need to show different content for page with different ID.

For do that i can use a conditional statement based on page id.

<!-- Test if are on page -->
[[*id:eq=`21`:then=`<link rel="canonical" href=""/>`:else=``]]

id:eq=`21` identify the page id, :then identify the content to show if we are on page with ID 21

here you can find all  input and Output Filters (Output Modifiers) for MODX