Simplify the following text for a Grade 4 native English-speaking person.
Original: He is best known for his starring roles in 17 Again with Zac Efron , in Sonny With a Chance as Chad Dylan Cooper with Demi Lovato , and in Starstruck as Christopher Wilde .
Simplified: He is in Sonny With a Chance as Chad Dylan Cooper . He also in plays Christopher Wilde in Starstruck .