swap 2 numbers in array java code example

Example 1: java array swap

public static void swap(int x, int y, int[] arr) {
  	int temp = arr[x];
  	arr[x] = arr[y];
  	arr[y] = temp;
}

Example 2: array.swap java

public static final <T> void swap (T[] a, int i, int j) {
  T t = a[i];
  a[i] = a[j];
  a[j] = t;
}

public static final <T> void swap (List<T> l, int i, int j) {
  Collections.<T>swap(l, i, j);
}

private void test() {
  String [] a = {"Hello", "Goodbye"};
  swap(a, 0, 1);
  System.out.println("a:"+Arrays.toString(a));
  List<String> l = new ArrayList<String>(Arrays.asList(a));
  swap(l, 0, 1);
  System.out.println("l:"+l);
}