Java - Changing variable value without accessing it

Question

I want to change the variable value without changing it directly, In C or C++ we may use pointers or reference variable to do that since no pointer concept in java, how we can do that.
in C we may do like this

int var=10;
int *ptr;
ptr=&var;
*ptr++;
printf("%d",var);

output :11
Is there is any other way to do same thing in java ?

Thanks in advance.

In Java everything is a reference (slap me if I'm slightly off). — Tim Biegeleisen, Jul 24 '17 at 11:38
Java has pointers, but you cannot manipulate them like in C++ or C — Kenneth Clark, Jul 24 '17 at 11:39
@TimBiegeleisen can you please give me simple code snippet using reference.please — Raj kumar, Jul 24 '17 at 11:39
https://stackoverflow.com/questions/1750106/how-can-i-use-pointers-in-java — Kenneth Clark, Jul 24 '17 at 11:40
You *are* accessing the variable. You're dereferencing the pointer. — matt, Jul 24 '17 at 11:45
What do you mean by "change the variable value without changing it directly"? You either set the variable to a value, or you don't. — Dawood ibn Kareem, Jul 24 '17 at 11:52

CodedStingray · Answer 1 · 2017-07-24T11:47:36.720

3

All the primitive types in Java (byte, short, int, long, float, double, boolean, char) are call by value, so with these, no, you can't do it. You can do it with objects though, as those are references.

Example:

public class MyInt {
    public int value;
}

public static void main(String args[]) {
    MyInt i1 = new MyInt();
    i1.value = 2;
    MyInt i2 = i1;
    i2.value++;
    System.out.println(i1.value);
}

edited Jul 24 '17 at 11:47

answered Jul 24 '17 at 11:41

CodedStingray

390
1
10

your example is missing – Tim Jul 24 '17 at 11:42
sorry messed up, added it now ^^ – CodedStingray Jul 24 '17 at 11:44
Example please. – Raj kumar Jul 24 '17 at 11:44
what does it print? – Tim Jul 24 '17 at 11:45
it prints 3, as bothi1 and i2 are references to the same object – CodedStingray Jul 24 '17 at 11:47

Java - Changing variable value without accessing it

1 Answers1