use bevy::{app::schedule_runner::ScheduleRunnerPlugin, prelude::*}; fn main() { App::build() .add_plugin(ScheduleRunnerPlugin::run_once()) // only run the app once so the printed system order is clearer .add_startup_system(startup_system.system()) .add_system(normal_system.system()) .run(); } /// Startup systems are run exactly once when the app starts up. /// They run right before "normal" systems run. fn startup_system() { println!("startup system ran first"); } fn normal_system() { println!("normal system ran second"); }