How can I simulate passing by reference in Java?

Question

I am a complete Java noob. I know that Java considers all parameters to be passed by value, and there are several others to where people explain this.

For example, in C ++, I can do:

void makeAThree(int &n)
{
   n = 3;
}
int main()
{
   int myInt = 4;
   makeAThree(myInt);
   cout << myInt;
}

What will be output 3. I know that in Java all parameters are passed by value, and therefore you cannot manipulate the passed parameter. Is there a standard way to simulate passing by reference in Java? Is it impossible to call a function that controls the passed variable? It’s hard for me to wrap up the idea that there is no way to do this.

Answer 1

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static void makeAThree(Reference<Integer> ref)
{
   ref.set(3);
}

public static void main(String[] args)
{
  Reference<Integer> myInt = new Reference<>(4);
  makeAThree(myInt);
  System.out.println(myInt.get());
}

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public class Reference<T> {
    private T referent;

    public Reference(T initialValue) {
       referent = initialValue;
    }

    public void set(T newVal) {
       referent = newVal;
    }

    public T get() {
       return referent;
    }
}

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Answer 2

1

Answer 3

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void someMethod()
{
   int value = 4;
   changeInt(value);
   System.out.printlin(value); 
}

public void changeInt(int x)
{
   x = x + 1;
}

4,

class SomeClass
    {
       int x;
    }

void someMethod()
    {
       SomeClass value = new SomeClass();
       value.x = 4;
       changeCls(value);
       System.out.printlin(value.x); 
    }

    public void changeCls(SomeClass cls)
    {
        cls = new SomeClass();
        cls.x = 5;
    }

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class SomeClass
{
   int x;
}

void someMethod()
    {
       SomeClass value = new SomeClass();
       value.x = 4;
       changeCls(value);
       System.out.printlin(value.x); 
    }

    public void changeCls(SomeClass cls)
    {
        cls.x = cls.x + 1;
    }

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Answer 4

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int[] int , 5 someMethod().

---

public void changeInt(int x)
{
   x = x + 1;
} 

---

public void changeInt(int[] x)
{
   x[0] += 1; 

}

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---

  public void changeCls(SomeClass cls)
   {
       cls = new SomeClass();
       cls.x = 5;
   }

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Answer 5

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Answer 6

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public static void main (String [] args) {
    int myInt = 4;
    myInt = makeAThree(myInt);

}
static int makeAThree(int n)
{
   return n = 3;
}

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Answer 7

Java pass by value .

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, java value.period.

Answer 8

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