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Overriding Doubt

 
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Hi All,

Here is my programme.

<code>
class Parent {
public int doStuff(float y) {
return 4;
}
}

public class OverridingTest extends Parent {
public Integer doStuff(float y) {
return 2;
}

public static void main(String[] args) {

}
}
</code>

After compiling this I am getting the following error.

OverridingTest.java:8: doStuff(float) in OverridingTest cannot override doStuff(
float) in Parent; attempting to use incompatible return type
found : java.lang.Integer
required: int
public Integer doStuff(float y) {
^
1 error

My doubt is, when the return type is Integer I should be able to return int primitive, I mean, auto boxing should work here. Why this code is not getting compiled?

Thanks & Regards,
Surya.
[ November 12, 2006: Message edited by: Sai Surya ]
 
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The override is not following valid overriding rule the return type should be same or should be covariant return type(you can refer to the K&B book for the rules).
To make it compilable either change the return type of either methods equals to other ones return type.
OR(Covariant returns)
 
Sai Surya
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Thanks Sanjeev!

Howerver, my doubt is, why auto boxing NOT taking place when I return int value for Integer return type?

- Surya.
 
Sanjeev Singh
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why auto boxing NOT taking place when I return int value for Integer return type?


The Autoboxing takes places but the overridding method is not a valid one (does not sticks to the rules of legal overrides).
 
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