“It was amazing when they asked us to do ‘Frenemies,’ ” the 15-year-old Coleman said during a joint telephone interview with Thorne from the “Shake It Up” set in Hollywood. “Bella is definitely my best friend. Just the fact that I got to do another project working with someone I already love, it made the experience 100 times more fun.”

“I knew that Zendaya would always be there on her spot,” the 14-year-old Thorne said. “She’s so talented and beautiful, and everything I gave, I got in return. She’s my honey-boo, and I’m very thankful that they let us do it together.”

“Frenemies”, which premiered last night, follows the overlapping stories of three sets of friends who become enemies. Thorne plays Avalon to Coleman’s Halle, and Avalon and Halle end up at each other’s throats when someone offers to buy their fashion webzine but wants only one of them to stay on board as editor.

“Halle is the nerd,” Coleman said. “Avalon is the glamorous one, and I’m the nerd who does all the writing for the blog. So I’m the quieter, more reserved one who likes to keep her voice and her comments to herself. It’s actually fun to watch her grow throughout the movie and get out of her shell a little.”

“We actually didn’t want to let too much of CeCe and Rocky into our performances,” Thorne added. “It was a little difficult, to be honest. I think we were a lot like CeCe and Rocky at the table read, but we learned to really know our characters and grow through our characters.”

Coleman concurred.

“One of the main things I wanted to do was separate my characters as much as possible,” she said. “When you watch the movie, you’ll see that my character wears glasses. I asked for glasses, which I felt was something I could use to give Halle some personality as well as differentiate her from Rocky. That was one thing, and then it just took some time to learn about the characters and dive into who they were.”

Even as “Frenemies” premieres, new episodes of “Shake It Up” will air. The show, in its second season, follows the exploits of CeCe and Rocky, who are backup dancers on their favorite dance show, “Shake It Up, Chicago.”

“Shake It Up” initially faced a rocky road, since it had the daunting task of replacing “Hannah Montana” (2006-2011), but it has all worked out: “Shake It Up” ranks as television’s top-rated series among the important “tween” audience of kids ages 9 to 14.

“I don’t think we really felt pressure,” Thorne said. “What we were really focused on was working on our show and trying to make it as good as it could possibly be. So we were just working hard and focusing on our own energy. There was pressure inside ourselves to make the show a hit, but we never really compared ourselves (to “Hannah Montana”). We felt that we were a different show, individual and different.”

” ‘Hannah Montana’ was amazing, obviously,” Coleman said, “but, like Bella said, we just try really hard to make it the best that it can be. We’re so humbled and thankful for the fans’ love. We’re actually shocked. Even now I’ll see my face on a billboard and I’ll start screaming. It’s so shocking, and I never thought it could happen to us.”

Thorne, who was born in Florida, has been acting since 2003 and counts among her 20-plus credits guest shots on “Entourage” (2007) and “Wizards of Waverly Place” (2009), and recurring roles on “Dirty Sexy Money” (2007), “Big Love” (2009) and “My Own Worst Enemy” (2009). Coleman, who lately is billing herself by the single name Zendaya, a la Cher or Madonna, hails from Oakland, Calif. She modeled and sang and danced in local theater productions before landing “Shake It Up.”

The show has put both actresses on the map, on the covers of a slew of teen magazines and on those posters Coleman mentioned. There’s even a “Shake It Up” fashion line. Also, each young lady has been recording and releasing songs and accompanying music videos.

Sudden fame has gotten the better of many young actors and actresses, including a few Disney starlets, so Thorne and Coleman often turn to each other when they feel the need to laugh, cry or vent in their effort to stay grounded.

“I’m really glad that I have Zendaya,” Thorne said. “To know that she’ll always be there for me in a tough situation I think it would be a lot harder if it was just a one-on-one and if we weren’t best friends. So I’m really glad I have her.”

“Honestly, I couldn’t imagine doing a show by myself,” Coleman said. “It’s such hard work, and you’re doing so much. To be alone throughout the process, I couldn’t do it. To have someone with me, to really support me and be with me through the entire ride, someone I can bond with and who I know has been through the same things I’m going through, it just makes the whole experience way, way better.”

Not that Coleman wants anyone to feel sorry for her.

“Most of all, (fame) is extraordinary,” she said. “I think it’s a beautiful thing. I prepared myself for it. I feel like I signed up for this, and I knew that this was something I wanted to do with my life. I feel like I was ready. I feel like I was preparing my entire life. So it’s an extraordinary feeling, and I love it.

“It comes with its downfalls,” Coleman admitted. “You get nervous. You don’t know how people are going to handle you. You have to be more cautious, but that’s OK. And I’m not a bad girl or anything like that. I’m definitely like Rocky, so I don’t have to worry too much about that.”