Why can ArrayList elements not be converted to ints?

Question

I know I have done this in the past. I have an ArrayList that has been populated with integers. I need to iterate over it and find the maximum value. However, when I iterate over an array with something like this:

for (int i = 0; i < list.size(); i++)
{
    if (list.get(i) > max)
    { 
        max = list.get(i);
    }
}

I get an error that says java.lang.Object cannot be converted to int or that > is a bad operand type. I have never encountered this before, and I have used arraylists multiple times for this same purpose. What am I doing wrong here?

max is declared as an int but is not initialized.

Answer 1

你很可能就像这样声明了ArrayList：

ArrayList list = new ArrayList<>();

而不是：

ArrayList<Integer> list = new ArrayList<>();