Casting

Java is very strict about types

• If a variable is declared to have the type X, you can only invoke operations on it that are defined in class X or its superclasses

  • Even though an instance of a subclass of X may be actually stored in the variable
• If you know an instance of a subclass is stored, then you can cast the variable to the subclass

  • E.g. if I know a Vector contains instances of String, I can get the next element of its Iterator using:
    (String)iterator.next();

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