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mock exam question

Frank Hale
Ranch Hand

Joined: Mar 25, 2000
Posts: 230
Could somebody explain to me why this program as this behavior?
public class test {

public static void main(String[] args)
{
Integer a = new Integer(0);
Integer b = new Integer(0);
System.out.println(a.equals(b)); // True
System.out.println(a==b); // False
}
}
Why aren't both lines true? zero does infact equal zero correct or I am totally confused.
Thanks,
Frank
Ankur Gupta
Ranch Hand

Joined: Jun 13, 2000
Posts: 66
equals() checks for the exact content in the two memory locations where the two objects 'a' and 'b' are. == checks the exact memory locations where the two objects are, and if they r same it returns true. Dose it make sense ?
Frank Hale
Ranch Hand

Joined: Mar 25, 2000
Posts: 230
Yes thank you. I've just started looking at mock exam questions and although I do program in Java quite alot I still have alot of work to do in order to get ready for the real exam. Thank you for clearing up my question.
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: mock exam question