Well, it's iteratiive, but where is the performance? :) It's a simple linear algorithm, while exponentiation by squering workis in `O(log n)`. I was suggesting to implement something like this (a^b) for numbers:

```java
int expo(int a, int b){
  int result = 1;

  while (b){
    if (b%2==1){
      result *= a;
    }
    b /= 2;
    a *= a;
  }

  return result;
}
```