Check if term object is in array

WordPress has the wp_list_pluck function, which can be helpful here. We can make an array of just term IDs from the array of objects like:

$term_ids = wp_list_pluck( $subcat_terms, 'term_id' );

Then we can check in_array:

$this_id = 42;
if( in_array( $this_id, $term_ids ) ){ // do something }