Charles Ellicott Commentary 2 Chronicles 24:2

"And Joash did that which was right in the eyes of Jehovah all the days of Jehoiada the priest." — 2 Chronicles 24:2 (ASV)

And Joash did. —See 2 Kings 13:3.

All the days of Jehoiada the priest. —Kings says: all his days, while (or because) Jehoiada the priest instructed him. The expression “all his days” is, of course, relative to the clause that follows it; and the Chronicler has accurately given the meaning.