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Problem with return type in an overriden method

 
Xavier Figueroa
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Java Netbeans IDE Spring
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Given this code:


if i run this code i get

Why I need to cast (String)a.voice() if the method called is a Dog Class member and has a String return type?
if i put the cast, y get
bark
 
Martin Vajsar
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You've declared the variable as Animal, and Animal.voice() returns Object. Although you know that the variable a contains an instance of Dog, the compiler does not "know" it and therefore expects that a.voice() returns Object.

This behavior of the compiler is not an error, it was designed this way. This is a trivial case. However, there might be cases in which such conclusions about actual type of a variable (if at all possible) might require extensive analysis. Therefore, the compiler follows a simple rule: a type of the variable is always determined by its declared type, regardless of its actual contents.
 
Martin Vajsar
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... and welcome to the Ranch!
 
Xavier Figueroa
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Thank you so much for your answer, I really needed this clarification and thanks for your Welcome
 
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