为什么存在未显示的元素？

Question

I am practicing creating a randomly generating integers in an array, then randomizing the elements in the array. All is well when I print the numbers, but there seems to be one element that does not print when I am displaying the randomized elements. Is there a step I am leaving out?

public class shufflingArrays {
public static void main(String[] args) {


    int[] myList = new int[10];
    System.out.println("Numbers:");
    for(int i = 0; i < myList.length; i++) {
        myList[i] = (int)(Math.random() * 100);
        System.out.print(myList[i] + " ");
    }
    System.out.println("\nRandomized:");

    for (int i = myList.length - 1; i > 0; i--){
        //Generate index j randomly with 0 <= j <= i
        int j = (int)(Math.random() * (i + 1));

        //Swap myList[i]; with myList[j]
        int temp = myList[i];
        myList[i] = myList[j];
        myList[j] = temp;
        System.out.print(myList[i] + " ");
    }   
}

Answer 1

Your for loop has condition i > 0 , which means when i == 0 it will terminate and not print out the first array element.

However, if you're doing the Fisher-Yates shuffle, as it appears, you do indeed need to go from myList.length-1 to 1, so your initial code was correct. You then can't print out all the elements in the array from the same loop, so either use another loop after to print out the elements, or add System.out.print(myList[0]); after.

Answer 2

Ex: for (int i = 4; i > 0; i--)

will run the for loop when i = 4, 3, 2, 1 only and not when i = 0 , because the condition there is i > 0 . Change the i > 0 condition in for (int i = myList.length - 1; i > 0; i--) to i >= 0 and you will get what you want.