Classes and objects in Java must be initialized before they are used. You’ve previously learned that class fields are initialized to default values when classes are loaded, and that objects are ...

Nested classes are classes that are declared as members of other classes or scopes. Nesting classes is one way to better organize your code. For example, say you have a non-nested class (also known as ...

正体不明のオブジェクトのクラスを調べるには？ J2SEのコアパッケージでも頻繁に利用されていますが，コレクションクラスを利用していると，格納されているオブジェクトがわからなくて戸惑うことがあります。コレクションはすべてObjectとして保持する ...

It's not good enough to simply write code that works. That code must be easily maintained, enhanced and debugged when problems happen. One of the reasons why object-oriented programming is so popular ...

Community driven content discussing all aspects of software development from DevOps to design patterns. The key difference between the Java int and Integer types is that an int simply represents a ...