Credit: Jordan Strauss/; Angela Weiss/Getty

Zac Efron's a friend indeed to Rumer Willis.

The actor, 24, has long been pals with the fledgling actress, 23, who was at her mom Demi Moore's side the night of her harrowing collapse and instantly infamous 911 call two weeks ago.

"Yeah, she's doing OK. She's doing fine," Efron told E! News of Willis while promoting his voiceover role in the new animated film, Dr. Seuss' The Lorax. "It's tough, but I think she's all right."

Sending his good vibes to Moore, 49, Efron added in a chat with Extra: "Me and Rumer have been friends for a long time. I know Demi is going through some personal stuff right now. I just wish her well. I hope she's doing okay."

The High School Musical hunk spent time with the troubled Margin Call star -- who was partying hard and hanging with her daughter's pals in the wake of her Ashton Kutcher split before her hospitalization and top-secret rehab stay.

Moore (who texted and called Efron) even "tracked down" the young hunk at a party in L.A.'s Venice neighborhood, an insider told Us Weekly. "She seemed out of her mind at this party."