Question

Analyze the following code:

A. When assigning s to o in Object o = s, a new object is created.
B. When casting o to s in String d = (String)o, a new object is created.
C. When casting o to s in String d = (String)o, the contents of o are changed.
D. s, o, and d reference the same String object.

Answer 1

The variables s, o, and d in the code provided all reference the same String object. No new object is created during assignment or casting, and the contents of the object are not changed during casting.

Step-by-step explanation:

The code segment you're asking about pertains to Java object referencing and type casting behavior. Let's analyze each statement:

• A. When assigning s to o in Object o = s;, a new object is not created. Instead, o is simply another reference to the same String object that s refers to.
• B. When casting o to s in String d = (String)o;, again a new object is not created. This cast operation just tells the compiler that you are sure o is of type String, so it can be treated as such.
• C. The contents of o are not changed when casting. The object that o references remains the same before and after the cast.
• D. The variables s, o, and d indeed reference the same String object after these operations, provided that o was a String originally when the cast was made.

In Java, all variables of object types are references. Thus assignment or casting operations do not duplicate the objects themselves but only work with the references.