fn guarded_approach_to_smoking(studies: vec<string>, user_interest: &str) { let message = "studies show precursory results on smoking impacts; for a healthier lifestyle, do not obey urges to reinitiate from the beginning."; if user_interest.contains("guarded") { for study in studies { println!("{} suggests guarded optimism.", study); } } else { println!("{}", message); } }