Return by Reference/Return by Value

Question

Okay. I am suppose to create this accessor method that is not suppose to return by reference so as to protect the private variables.
Firstly, I suppose for primitive data type I can :
public int rtnInt() {
int i = 0;
int j;
int j = i;//Primitive type creates new memory for variable
return j; }
Right? Or can I just return i? Will returning i result as a reference to i?
Secondly, I am stumped on reference data type, example if I have :
public String rtnstr() {
String a = "a"
String b;
String b = a; //Can't do this right, it will just reference to the location of a?
return b;
So how do you actually copy a new a to and assign it to b? Oh ya, am I right to say arraycopy copies a new array and I don't have to worry about referencing?

Answer 1

Noobie1987 wrote:
Eh? So you mean to say I can just return or pass any variables, reference or primitive type, without fear of the original being modified?"Returning variables" does not pertain here, since when you return from a method, the variables are popped from from the stack and cease to exist. When you pass a variable to a method, a copy of that variable's value is used within the method. Changing the variable within the method does not affect the variable outside the method. Ever.
But I thought 2 variables referencing the same memory location will affect each other if a change is made. AKA...
String[] str = {0};
String[] abc = str;
abc[0] = 1;
So str[0] will become 1?First, that example won't compile. Second, there is no passing of anything; just variable assignment.
It is important to understand that variables do not contain objects. Read this: [http://www.javaranch.com/campfire/StoryPassBy.jsp]
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