question about access modifier

[manu lix]

Which lines have compilation problems ?

public class Test extends Abs // #1
{
    public static void main(String[] args) // #2
    {
        Abs interface1 = new Test(); // #3
    }
    
}

abstract class Abs // #4
{
    String toString(){return null;} // #5 
    public int hashCode(){return (int)(-1*System.currentTimeMillis());} // #6
}

Options:

1.) # 1

2.) # 2

3.) # 3

4.) # 4

5.) # 5

6.) # 6

The compile-time erros is at #5, ma why?
In abstract class the access modifier are public and abstract, right?
Then, why the reason of the error is that public method cannot be restricted to a default method?

Thanks in advance for help

[Henry Wong]

Please QuoteYourSources.

Henry

[manu lix]

CertPal

[Raymond Tong]

If you change your method name from toString to something else, it should works.
You are actually overriding toString method (and reducing the access level from public to default)
All classes implicitly extends Object which has toString method http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#toString()

[manu lix]

Raymond Tong wrote:If you change your method name from toString to something else, it should works.
You are actually overriding toString method (and reducing the access level from public to default)
All classes implicitly extends Object which has toString method http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#toString()

Ok, I agree!
But, in abstract class the methos are implicity public and astract, so:

abstract class Abs // #4
{
    String toString(){return null;} // #5 
    public int hashCode(){return (int)(-1*System.currentTimeMillis());} // #6
}

toString() are public even if it has not been spelled out, ok?

[Henry Wong]

manu lix wrote:
But, in abstract class the methos are implicity public and astract, so:

Really? Can you provide a pointer for this statement?

Henry

[manu lix]

Henry Wong wrote:

manu lix wrote:
But, in abstract class the methos are implicity public and astract, so:

Really? Can you provide a pointer for this statement?

Henry

Maybe, I am confused with interfaces

[Girish Bal]

manu lix wrote:

Maybe, I am confused with interfaces

Only in interfaces, the methods are public and abstract by default.