Iterator Pattern

• is very commonly used design pattern in Java
• This pattern is used to get a way to access the elements of a collection object in sequential manner without any need to know its underlying representation(基本的な表現方法を知らなくても連続した方法でコレクションオブジェクトの要素にアクセスする方法を取得するのに使われる)
• collection class has a inner class(iterator class). that class can7t be used by other class.

Reference

• tutorialspoint:Iterator Pattern
• journaldev:Iterator Pattern
• geeksforgeeks:Iterator Pattern
• iluwatar:Iterator Pattern