// method
public static int [] copyArray(int [] arr){
int [] copyArr = new int[arr.length];
for (int i = 0; i < copyArr.length; i++){
copyArr[i] = arr[i];
}
return copyArr;
}
// Arrays. method
int[] copyCat = Arrays.copyOf(arr, arr.length);
// System
System.arraycopy(x,0,y,0,5); // 5 is array's length
// clone
y = x.clone();