pass by reference?

[wayenng]

Hi all,

I am new on Java, I don't why the final answer is from the below.


Question: What is the output from the following code:

IdentifyMyParts a = new IdentifyMyParts();
IdentifyMyParts b = new IdentifyMyParts();
a.y = 5;
b.y = 6;
a.x = 1;
b.x = 2;
System.out.println("a.y = " + a.y);
System.out.println("b.y = " + b.y);
System.out.println("a.x = " + a.x);
System.out.println("b.x = " + b.x);
System.out.println("IdentifyMyParts.x = " +
IdentifyMyParts.x);
Answer: Here is the output:

a.y = 5
b.y = 6
a.x = 2
b.x = 2
IdentifyMyParts.x = 2



Please advise.
source:
Answers to Questions and Exercises: Classes (The Java™ Tutorials > Learning the Java Language > Classes and Objects)

[eRaaaa]

The explanation stands still underneath?
"Because x is defined as a public static int in the class IdentifyMyParts, every reference to x will have the value that was last assigned because x is a static variable"

Understanding Instance and Class Members (The Java™ Tutorials > Learning the Java Language > Classes and Objects) - static keyword

[wayenng]

The explanation stands still underneath?
"Because x is defined as a public static int in the class IdentifyMyParts, every reference to x will have the value that was last assigned because x is a static variable"

Understanding Instance and Class Members (The Java™ Tutorials > Learning the Java Language > Classes and Objects) - static keyword

then i have confuse that y should also be a static variable, right?
if yes, then why the overall answer is not like below,
a.y = 6
b.y = 6
a.x = 2
b.x = 2

Please advise.
Thanks.

[eRaaaa]

? No why? y isn`t a static variable!

[wayenng]

Thanks for reply.
Pls accept my apologize that i am just new on java.
Thus i can not realize clearly on how to know that y is non-static.
would you mind telling me instead?

Thanks a lot.

[eRaaaa]

public class IdentifyMyParts {
    public static int x = 7;
    public int y = 3;
}

static int x;
and only int y; there is no static ?
did you read my link? -> Understanding Instance and Class Members (The Java™ Tutorials > Learning the Java Language > Classes and Objects)

[DarrylBurke]

About the subject line: there is no pass-by-reference in Java. Primitives are passed by value. References are passed by value. Objects are not passed at all.

db

[wayenng]

I am really sorry about that I have overlooked the

public class IdentifyMyParts {
public static int x = 7;
public int y = 3;
}

which stated at the beginning...i have just focused on the Q1 part C at all....
anyway, i am now realize why the answer is...

Thanks a lot eRaaa for your patient.