Why was david anointed king while saul was stilll in charge of the lsraelites?

David was anointed king while Saul was still in charge because God had rejected Saul as king due to his disobedience and failure to follow divine commands. The prophet Samuel was instructed by God to anoint David as Saul's successor to prepare for a transition in leadership. This anointing was meant to signify God's choice of David as the future king of Israel, despite Saul remaining in power at that time. The situation ultimately set the stage for the conflicts and events that followed in the biblical narrative.