Class 18 Practice Exercise

Aliasing exercise

Write the function
```
void swap(int a, int b)
```
meant to swap the values of a and b. That is, if I say
```
void setup()
{
  int x = 5;
  int y = 10;

  swap(x, y);

  println(x);
  println(y);
}
```
I should expect to see 10 followed by 5 in my output.

You actually won’t be able to get this to work. But write the swap function anyway, and write printlns in your swap function to demonstrate that it really does swap a and b, even though the x and y in setup do not get swapped.
Write the function
```
void swap(int[] a, int[] b)
```
where a and b are assumed to be 1-element arrays. (That is, a.length and b.length are both 1.) Set up a similar situation to problem (1) in your setup function to test your new swap function. Here, you should observe that your swap function does work.
Write the function
```
void swap(MutableInteger a, MutableInteger b)
```
where you have pasted the code from the MutableInteger class into a second tab in your Processing window. (It’s available on our course webpage.) This also should work.