Method returns true even though it should not. Possible complication with for loop

Question

I'm quite new to Java so please bear with me. I wrote this program:

public static void main(String args[])
{
    int[] list = {1, 1, 2, 2, 3, 4, 5, 6, 7, 8, 10};
    isUnique(list);
    System.out.println(isUnique(list));

}

private static boolean isUnique(int[] array) 
{
    int count = 0;

    for (int n : array)
    {
        for (int i = 0; i < array.length; i++)
        {
            if (n == array[i])
            {
                count++;
            }
            if (count > 1)
            {
                return false;
            }
            else 
            {
                return true;
            }
        }
    }
    return false;
}

}

It's supposed to check the array and see, if there are any more than 1 of each number. However it doesn't seem to work. It returns true even if there are two 1's. Any ideas? I suspect the for loop isn't working, but I'm not quite sure why.

Thanks in advance!

Answer 1

It returns true no matter what because you have that else block. Because count starts up zero and it increases a maximum of one time per loop, that else block will always run (if the array length is not 0). You can think of this as two cases:

Case 1. n == array[i] --> count will equal 1 --> count>1 is not true --> else block runs and returns true.

Case 2. n is not array[i] --> count equals 0 --> count>1 is not true --> else block runs and returns true