When an array is passed to a method, what is actually passed?

When an array is passed to a method in Java, what is actually passed is the reference to the array object. This means that the method receives a pointer to the original array in memory rather than a copy of the array itself. As a result, any modifications made to the array within the method will affect the original array outside the method.

This behavior is due to Java's handling of objects and references. In Java, when you pass an object (including arrays, which are also objects) to a method, you are passing the reference to that object. Thus, if the method alters the contents of the array, those changes will be reflected in the original array, as both the method and the caller are referring to the same object in memory.

Understanding this concept is crucial for effective programming in Java, as it influences how data can be manipulated across different methods and highlights the importance of managing references carefully to avoid unintentional side effects.