When I first learned to program, it was grasping if statements that helped it all click into place for me. Once you can use if statements, you can build all kinds of useful and interesting tools.

「通常の教科書的な書き方」と別の書き方 実務では必ず終了条件 or break、または待機/sleepを入れる（CPUを焼かない）。 while ...