The juvenile court did not err by dismissing part of a petition where dismissal was in the minor’s best interest. After a true finding at the jurisdictional hearing, the juvenile court dismissed the section 300, subdivision (a) petition, and one allegation from the section 300, subdivision (b) petition at the request of the department pursuant to section 390. On appeal, the father contended that the court prejudicially erred because section 390 permits a dismissal of the entire petition, but not part of the petition after a true finding. He contended he was prejudiced by the court’s ruling because he was denied his right to challenge the modified petition. The appellate court rejected the argument and affirmed. The amendments conformed the allegations of the petition to the proof and did not cause the father any prejudice. The section 390 motion provided the parties with notice and the court conducted a hearing and provided the father the opportunity to be heard. Dismissal of the entire petition and refiling was not in the minor’s best interest because it would cause unnecessary delay.