编写此函数的更好方法是什么？

Question

I have to go through an array and print out whether it's sorted or not, and if it isn't - print out the first two elements that are not sorted (eg: 6 > 5).

So I was wondering what would be considered the best way to do this with a function:

1. Make a void function which prints out either "It's sorted" or "It's not sorted" and if it's not it prints out the two elements as well.
2. Make a boolean function which prints out the two unsorted elements (if there are any) and eventually returns either true or false. Then depending on what the function returns, print out whether the array is sorted in the main .
3. Do everything in the main as this could be not appropriate for a function?
4. Some other way?

Note that I'm not asking for any help regarding my assignment itself!

Answer 1

I would create a function that returns the index of the last sorted cell, so if it is the last cell then everything is sorted and if it is smaller than you can easily find also the next element and print in main. I don't think that functions should have side affects (like print) when they are made for other purpose, and a function like this one that returns index is what you can use:

private int getFirstSortedIndex(int[] numbers){
   int index = 0;
   //find and return the first sorted index;
   return index;
}

public static void main(String[] args){
   int[] numbers;
   //get the array from user input or arguments
   int index = getFirstSortedElement(numbers);
   if( index < numbers.length-1){
      //print numbers[index] and numbers[index+1]
   } else{
      //print "it's sorted"
   }
}

Answer 2

I would create a method that returns the index of the first element that is not correctly ordered:

/**
 * @param array ordered array
 * @return the index of the first unordered element, or -1 if the array is ordered
 */
static int isOrdered(int[] array) {
    // iterate through the array
    //     if a two sequential elements are not ordered, return the index of the first element
    // if all is ok, return -1
}

And then do:

int unsortedIndex = isOrdered(array);
if (unsortedIndex != -1) {
    System.out.println(array[unsortedIndex] + ", " + array[unsortedIndex + 1]);
}

This is better than printing the elements directly in isOrdered() , because now you can reuse isOrdered() in other parts of the code if you need to.