`get_terms()` has historically required that a taxonomy be specified when
querying terms. This requirement is related to the fact that terms could
formerly be shared between taxonomies, making `$taxonomies` critical for
disambiguation. Since terms can no longer be shared as of 4.4, it'
s desirable to be able to query for terms regardless of what taxonomy they're in.
Because it's now optional to pass taxonomies, it's no longer necessary to have
`$taxonomies` as the first (and required) parameter for `get_terms()`. The new
function signature is `get_terms( $args )`, where 'taxonomy' can (optionally) be
passed as part of the `$args` array. This syntax is more consistent with
functions like `get_users()` and `get_posts()`.
We've maintained backward compatibility by always giving precedence to the old
argument format. If a second parameter is detected, or if it's detected that
the first parameter is a list of taxonomy names rather than an `$args` array,
`get_terms()` will parse the function arguments in the legacy fashion.
Props flixos90, swissspidy, DrewAPicture, boonebgorges.
Fixes#35495.
git-svn-id: https://develop.svn.wordpress.org/trunk@36614 602fd350-edb4-49c9-b593-d223f7449a82
408fb37f2b